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='''REVISION REQUEST 4023'''=
='''REVISION REQUEST 4036'''=


===751.24.2.1 Design===
==106.3.2.93.1 Means of Evaluating Aggregate Alkali Carbonate Reactivity==


Designs of Mechanically Stabilized Earth (MSE) walls shall be completed by consultants or contractors in accordance with Section 11.10 of LRFD specifications, FHWA-NHI-10-024 and FHWA-NHI-10-025 for LRFD. [https://www.modot.org/bridge-pre-qualified-products-list Bridge Pre-qualified Products List (BPPL)] provided on MoDOT's web page and in Sharepoint contains a listing of facing unit manufacturers, soil reinforcement suppliers, and wall system suppliers which have been approved for use. See [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=11 Sec 720] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=14 Sec 1010] for additional information. The Geotechnical Section is responsible for checking global stability of permanent MSE wall systems, which should be reported in the Foundation Investigation Geotechnical Report. For MSE wall preliminary information, see [[751.1_Preliminary_Design#751.1.4.3_MSE_Walls|EPG 751.1.4.3 MSE Walls]]. For design requirements of MSE wall systems and temporary shoring (including temporary MSE walls), see [[:Category:720_Mechanically_Stabilized_Earth_Wall_Systems#720.2_Design_Requirements|EPG 720 Mechanically Stabilized Earth Wall Systems]]. For staged bridge construction, see [[751.1_Preliminary_Design#751.1.2.11_Staged_Construction|EPG 751.1.2.11 Staged Construction]].
'''1. Chemical Analysis'''


For seismic design requirements, see [https://epg.modot.org/forms/general_files/BR/Bridge_Seismic_Design_Flowchart.pdf Bridge Seismic Design Flowchart]. References for consultants and contractors include Section 11.10 of LRFD, FHWA-NHI-10-024 and FHWA-NHI-10-025.
The chemical analysis of aggregate reactivity is an objective, quantifiable and repeatable test.  MoDOT will perform the chemical analysis per the process identified in ASTM C 25 for determining the aggregate composition.  The analysis determines the calcium oxide (CaO), magnesium oxide (MgO), and aluminum oxide (Al<sub>2</sub>O<sub>3</sub>) content of the aggregate.  The chemical compositions are then plotted on a chart with the CaO/MgO ratio on the y-axis and Al<sub>2</sub>O<sub>3</sub> percentage on the x-axis per Fig. 2 in AASHTO R 80. Aggregates are considered potentially reactive if the Al<sub>2</sub>O<sub>3</sub> content is greater than or equal to 1.0% and the CaO/MgO ratio is either greater than or equal to 3.0 or less than or equal to 10.0 (see chart below). See flow charts in 106.3.2.93.2 for approval hierarchy. CaO, MgO and Al2O3 shall be analyzed by instrumental analysis only.


'''Design Life'''
[[File:106.3.2.93.1_Potentially_Expansive_Aggregate_Limits-01.png|700px]]


* 75 year minimum for permanent walls (if retained foundation require 100 year than consider 100 year minimum design life for wall).
<nowiki>*</nowiki> MoDOT’s upper and lower limits of potentially reactive (shaded area) aggregates.


'''Global stability:'''
'''2.  Petrographic Examination'''


Global stability will be performed by Geotechnical Section or their agent.
A petrographic examination is another means of determining alkali carbonate reactivity.  The sample aggregate for petrographic analysis will be obtained at the same time as the source sample.  MoDOT personnel shall be present at the time of sample.  The petrographic sample shall be placed in an approved tamper-evident container (provided by the quarry) for shipment to petrographer.  Per ASTM C 295, a petrographic examination is to be performed by a petrographer with at least 5 years of experience in petrographic examinations of concrete aggregate including, but not limited to, identification of minerals in aggregate, classification of rock types, and categorizing physical and chemical properties of rocks and minerals.  The petrographer will have completed college level course work in mineralogy, petrography, or optical mineralogy.  MoDOT does not accept on-the-job training by a non-degreed petrographer as qualified to perform petrographical examinations.  MoDOT may request petrographer’s qualifications in addition to the petrographic report.  The procedures in C 295 shall be used to perform the petrographic examination. The petrographic examination report to MoDOT shall include at a minimum:


'''MSE wall contractor/designer responsibility:'''
* Quarry name and ledge name; all ledges if used in combination
* MoDOT District quarry resides
* Date sample was obtained; date petrographic analysis was completed
* Name of petrographer and company/organization affiliated
* Lithographic descriptions with photographs of the sample(s) examined
* Microphotographs of aggregate indicating carbonate particles and/or other reactive materials
* Results of the examination
* All conclusions related to the examination 


MSE wall contractor/designer shall perform following analysis in their design for all applicable limit states.
See flow charts in EPG 106.3.2.93.2 for the approval hierarchy.  See EPG 106.3.2.93.3 for petrographic examination submittals.  No direct payment will be made by the Commission for shipping the petrographic analysis sample to petrographer, or for the petrographic analysis performed by the petrographer. 
 
'''3. Concrete Prism/Beam Test'''


:* External Stability
ASTM C 1105 is yet another means for determining the potential expansion of alkali carbonate reactivity in concrete aggregate.  MoDOT will perform this test per C 1105 at its Central Laboratory.  Concrete specimen expansion will be measured at 3, 6, 9, and 12 months. The test specimens will be considered alkali carbonate reactive (expansive) if the specimens expand greater than 0.015% at 3 months, 0.025% at 6 months, or 0.030% at 12 months. See flow chart in EPG 106.3.2.93.2 for the approval hierarchy.
::* Limiting Eccentricity
::* Sliding
::* Factored Bearing Pressure/Stress ≤ Factored Bearing Resistance
:* Internal Stability
::* Tensile Resistance of Reinforcement
::* Pullout Resistance of Reinforcement
::* Structural Resistance of Face Elements
::* Structural Resistance of Face Element Connections
:* Compound Stability
:: Capacity/Demand ratio (CDR) for bearing capacity shall be ≥ 1.0
:: <math>Bearing\ Capacity\ (CDR) = \frac{Factored\ Bearing\ Resistance}{Maximum\ Factored\ Bearing\ Stress} \ge 1.0</math>
:: Strength Limit States:
:: Factored bearing resistance = Nominal bearing resistance from Geotech report X Minimum Resistance factor (0.65, Geotech report) LRFD Table 11.5.7-1 


:: Extreme Event I Limit State:
:: Factored bearing resistance = Nominal bearing resistance from Geotech report X Resistance factor
:: Resistance factor = 0.9  LRFD 11.8.6.1


:: Factored bearing stress shall be computed using a uniform base pressure distribution over an effective width of footing determined in accordance with the provisions of LRFD 10.6.3.1 and 10.6.3.2, 11.10.5.4  and Figure 11.6.3.2-1 for foundation supported on soil or rock.


:: B’ = L – 2e
='''REVISION REQUEST 4143'''=
==751.36.5 Design Procedure==
*Structural Analysis
*Geotechnical Analysis
*Drivability Analysis


:: Where,
===751.36.5.1 Design Procedure Outline===
::: L = Soil reinforcement length (For modular block use B in lieu of L as per LRFD 11.10.2-1)
*Determine foundation load effects from the superstructure and substructure for Service, Strength and Extreme Event Limit States. 
::: B’ = effective width of footing
*If applicable, determine scour depths, liquefaction information and pile design unbraced length information. 
::: e = eccentricity
*Determine if downdrag loadings should be considered. 
::: Note: When the value of eccentricity e is negative then B´ = L.  
*Select preliminary pile size and pile layout.
*Perform a Static Pile Soil Interaction Analysis.  Estimate Pile Length and pile capacity.
*Based on pile type and material, determine Resistance Factors for Structural Strength (<math>\, \phi_c</math> and <math>\, \phi_f</math>).
*Determine:
**Maximum axial load effects at toe of a single pile
**Maximum combined axial & flexural load effects of a single pile
**Maximum shear load effect for a single pile
**Uplift pile reactions
*Determine Nominal and Factored Structural Resistance for single pile
**Determine Structural Axial Compression Resistance
**Determine Structural Flexural Resistance
**Determine Structural Combined Axial & Flexural Resistance
**Determine Structural Shear Resistance
*Determine method for pile driving acceptance criteria
*Determine Resistance Factor for Geotechnical Resistance (<math>\, \phi_{stat}</math>) and Driving Resistance (<math>\, \phi_{dyn}</math>).
*If other than end bearing pile on rock or shale, determine Nominal Axial Geotechnical Resistance for pile.
*Determine Factored Axial Geotechnical Resistance for single pile.
*Determine Nominal pullout resistance if pile uplift reactions exist.
*Check for pile group effects.
*Resistance of Pile Groups in Compression 
*Check Drivability of all pile (bearing and friction pile) using the Wave equation analysis.
*Review Static Pile Soil Interaction Analysis and pile lengths for friction pile.
*Show proper Pile Data on Plan Sheets ([https://epg.modot.org/index.php/751.50_Standard_Detailing_Notes#E2._Foundation_Data_Table Foundation Data Table]).


::Capacity/Demand ratio (CDR) for overturning shall be ≥ 1.0
===751.36.5.2 Structural Resistance Factor (ϕ<sub>c</sub> and ϕ<sub>f</sub>) for Strength Limit State===
::<math>Overtuning\ (CDR)  = \frac{Total\ Factored\ Resisting\ Moment}{Total\ Factored\ Driving\ Moment} \ge 1.0</math>
{| style="margin: 1em auto 1em auto"
|-
|align="right" width="850"|'''LRFD 6.5.4.2'''
|}


::Capacity/Demand ratio (CDR) for eccentricity shall be ≥ 1.0
'''For integral end bent simple pile design,''' use Φ<sub>c</sub>  = 0.35 for CIP steel pipe piles and HP piles.  See [[751.35 Concrete Pile Cap Integral End Bents#751.35.2.4.2 Pile Design|Figure 751.35.2.4.2]].
::<math>Eccentricity\ (CDR) = \frac{e_{Limit}}{e_{design}} \ge 1.0</math>


::Capacity/Demand ratio (CDR) for sliding shall be ≥ 1.0 &nbsp;&nbsp;&nbsp;&nbsp; LRFD 11.10.5.3 & 10.6.3.4
'''For pile at all locations where integral end bent simple pile design is not applicable,''' use the following:
::<math>Sliding\ (CDR)  = \frac{Total\ Factored\ Sliding\ Resistance}{Total\ Factored\ Active\ Force} \ge 1.0</math>


::Capacity/Demand ratio (CDR) for internal stability shall be ≥ 1.0
:The structural resistance factor for axial resistance in compression is dependent upon the expected driving conditions. When the pile is subject to damage due to severe driving conditions where use of pile point reinforcement is necessary:
::Steel Shells (Pipe): <math> \phi_c </math>= 0.60
::HP Piles: <math> \phi_c </math>= 0.50
:When the pile is subject to good driving conditions where use of pile point reinforcement is not necessary:
::Steel Shells (Pipe) Piles: <math> \phi_c </math>= 0.70
::HP Piles: <math> \phi_c </math>= 0.60
:For HP piles, pile point reinforcement is always required when HP piles are anticipated to be driven to rock and proofed. Driving HP piles to rock is considered severe driving conditions for determination of structural resistance factor. However, driving HP piles through overburden not likely to impede driving to deep rock or preboring to rock for setting piles are two situations that could be considered as less than severe. Further, driving any steel pile through soil without rubble, boulders, cobbles or very dense gravel could be considered good driving conditions for determination of structural resistance factor. Consult the Structural Project Manager or Structural Liaison Engineer.
:The structural resistance factor for combined axial and flexural resistance of undamaged piles:
::Axial resistance factor for HP Piles: <math> \phi_c </math>= 0.70
::Axial resistance for Steel Shells (Pipe): <math> \phi_c </math>= 0.80
::Flexural resistance factor for HP Piles or Steel Shells: <math> \phi_f </math>= 1.00
:For Extreme Event Limit States, see LRFD 10.5.5.3.
<div id="751.36.5.3 Geotechnical Resistance"></div>


::Eccentricity, (e) Limit for Strength Limit State: &nbsp;&nbsp;&nbsp;&nbsp; LRFD 11.6.3.3 & C11.10.5.4
===751.36.5.3 Geotechnical Resistance Factor (ϕ<sub>stat</sub>) and Driving Resistance Factor (ϕ<sub>dyn</sub>)===
::: For foundations supported on soil or rock, the location of the resultant of the reaction forces shall be within the middle two-thirds of the base width, L or (e ≤ 0.33L).
The factors for Geotechnical Resistance (<math> \phi_{stat}</math>) and Driving Resistance (<math> \phi_{dyn}</math>) may be different because of the reliability of the different methods used to determine the nominal bearing resistance. Caution should be used if the difference in factors for Geotechnical Resistance and Driving Resistance are great as it can lead to issues with pile overruns. Also see [[#751.36.5.9 Estimate Pile Length and Check Pile Capacity|EPG 751.36.5.9]].


::Eccentricity, (e) Limit for Extreme Event I (Seismic): &nbsp;&nbsp;&nbsp;&nbsp; LRFD 11.6.5.1
'''Geotechnical Resistance Factor, ϕ<sub>stat</sub>:'''
:::For foundations supported on soil or rock, the location of the resultant of the reaction forces shall be within the middle two-thirds of the base width, L or (e ≤ 0.33L) for  γ<sub>EQ</sub> = 0.0 and middle eight-tenths of the base width, L or (e ≤ 0.40L) for  γ<sub>EQ</sub> = 1.0.  For γ<sub>EQ</sub>  between 0.0 and 1.0, interpolate e value linearly between 0.33L and 0.40L. For γ<sub>EQ</sub>  refer to LRFD 3.4.


:::Note: Seismic design shall be performed for γ<sub>EQ</sub> = 0.5
The Geotechnical Resistance factor is based on the static method used by the designer in determining the nominal bearing resistance. Unlike the Driving Resistance factor the Geotechnical Resistance factor can vary with the soil layers. If Geotechnical Resistance factors are not provided by the Geotechnical Engineer, the static method and resistance factors shall be selected from the table below. The values provided in LRFD Table 10.5.5.2.3-1 are only applicable if the end of drive criteria is based off the total pile penetration which is not recommended. For Extreme Event Limit States see LRFD 10.5.5.3.


::Eccentricity, (e) Limit for Extreme Event II:
{|border="1" style="text-align:center; width: 750px" cellpadding="5" align="center"  cellspacing="0"
:::For foundations supported on soil or rock, the location of the resultant of the reaction forces shall be within the middle eight-tenths of the base width, L or (e ≤ 0.40L).
|+ '''Table - Static Analysis Resistance Factors used for Pile Length Estimates'''
! Pile Type !! Soil Type !! Static Analysis Method !! Side Friction<sup>1</sup><br><math> \phi_{stat}</math> !! End Bearing<br><math> \phi_{stat}</math>
|-
| rowspan="4" | '''CIP Piles - Steel Pipe Shells''' || Clay || Alpha - Tomlinson || <math> \phi_{dyn}</math><sup>2</sup> || <math> \phi_{dyn}</math><sup>2</sup>
|-
| rowspan="3" | Sand || Nordlund<sup>3</sup> || 0.45 - Gates<br>0.45 - WEAP<br>0.55 - PDA || 0.45 - Gates<br>0.45 - WEAP<br>0.55 - PDA
|-
| LCPC<sup>4</sup> || 0.70 || 0.45
|-
| Schmertmann<sup>5</sup> || 0.50 || 0.50
|}


'''General Guidelines'''
{|border="0" style="text-align:left; width: 750px" align="center"  cellspacing="0"
|-
| <sup>1</sup> For mixed soil profiles the lowest applicable resistance factor for clay or sand may be used to simplify the analysis.
|-
| <sup>2</sup>  ϕ<sub>dyn</sub> = see following section.
|-
| <sup>3</sup>The Nordlund method is recommended for sand layers in mixed soil profiles where CPT data is not available.
|-
| <sup>4</sup>The resistance factors associated with the LCPC method are not statistically calibrated for reliability, but studies have shown this method to be one of the most reliable methods for predicting soil behavior from CPT data.
|-
| <sup>5</sup>Per LRFD 10.7.3.8.6g the Schmertmann method shall only be used for sands and nonplastic silts with CPT data.
|-
| For more detailed guidance see [https://www.modot.org/media/54989 SEG 25-001 New Policy for Friction Pile].
|}


* Drycast modular block wall (DMBW-MSE) systems are limited to a 10 ft. height in one lift.
'''Driving Resistance Factor, ϕ<sub>dyn</sub>:'''


* Wetcast modular block wall (WMBW-MSE) systems are limited to a 15 ft. height in one lift.
The Driving Resistance factor shall be selected from LRFD Table 10.5.5.2.3-1 based on the method to be used in the field during construction to verify nominal axial compressive resistance.  


* For Drycast modular block wall (DMBW-MSE) systems and Wetcast modular block wall (WMBW-MSE) systems, top cap units shall be used and shall be permanently attached by means of a resin anchor system.
{|border="1" style="text-align:center;" cellpadding="5" align="center"  cellspacing="0"
 
! Pile Driving Verification Method !! Resistance Factor,<br/><math> \phi_{dyn}</math>
* For precast modular panel wall (PMPW-MSE) systems, capstone may be substituted for coping and either shall be permanently attached to wall by panel dowels.
|-
 
| FHWA-modified Gates Dynamic Pile Formula<br/>(End of Drive condition only) || 0.40
* For precast modular panel wall (PMPW-MSE) systems, form liners are required to produce all panels. Using form liner to produce panel facing is more cost effective than producing flat panels. Standard form liners are specified on the [https://www.modot.org/mse-wall-msew MSE Wall Standard Drawings]. Be specific regarding names, types and colors of staining, and names and types of form liner.
|-
 
| Wave Equation Analysis (WEAP) || 0.50
* MSE walls shall not be used where exposure to acid water may occur such as in areas of coal mining.
|-
 
| Dynamic Testing (PDA) on 1 to 10% piles || 0.65
* MSE walls shall not be used where scour is a problem.
|-
 
| Other methods || Refer to LRFD Table 10.5.5.2.3-1
* MSE walls with metallic soil reinforcement shall not be used where stray electrical ground currents may occur as would be present near electrical substations.
|}
 
* No utilities shall be allowed in the reinforced earth if future access to the utilities would require that the reinforcement layers be cut, or if there is a potential for material, which can cause degradation of the soil reinforcement, to leak out of the utilities into the wall backfill, with the exception of storm water drainage.
 
* All vertical objects shall have at least 4’-6” clear space between back of the wall facing and object for select granular backfill compaction and soil reinforcement skew limit requirements. For piles, see pipe pile spacers guidance.
 
* The interior angle between two MSE walls should be greater than 70°. However, if unavoidable, then place [[751.50_Standard_Detailing_Notes#J._MSE_Wall_Notes_.28Notes_for_Bridge_Standard_Drawings.29|EPG 751.50 J1.41 note]] on the design plans.
 
* Drycast modular block wall (DMBW-MSE) systems and Wetcast modular block wall (WMBW-MSE) systems may be battered up to 1.5 in. per foot. Modular blocks are also known as “segmental blocks”.
 
* The friction angle used for the computation of horizontal forces within the reinforced soil shall be greater than or equal to 34°.
 
* For epoxy coated reinforcement requirements, see [[751.5 Structural Detailing Guidelines#751.5.9.2.2 Epoxy Coated Reinforcement Requirements|EPG 751.5.9.2.2 Epoxy Coated Reinforcement Requirements]].
 
* All concrete except facing panels or units shall be CLASS B or B-1.
 
* The friction angle of the soil to be retained by the reinforced earth shall be listed on the plans as well as the friction angle for the foundation material the wall is to rest on.
 
* The following requirement shall be considered (from 2009_FHWA-NHI-10-024 MSE wall 132042.pdf, page 200-201) when seismic design is required:
:* For seismic design category, SDC C or D (Zones 3 or 4), facing connections in modular block faced walls (MBW) shall use shear resisting devices (shear keys, pin, etc.) between the MBW units and soil reinforcement, and shall not be fully dependent on frictional resistance between the soil reinforcement and facing blocks. For connections partially dependent on friction between the facing blocks and the soil reinforcement, the nominal long-term connection strength T<sub>ac</sub>, should be reduced to 80 percent of its static value.
 
* Seismic design category and acceleration coefficients shall be listed on the plans for categories B, C and D. If a seismic analysis is required that shall also be noted on the plans. See [[751.50_Standard_Detailing_Notes#A._General_Notes|EPG 751.50 A1.1 note]].
 
* Plans note ([[751.50_Standard_Detailing_Notes#J._MSE_Wall_Notes_.28Notes_for_Bridge_Standard_Drawings.29|EPG 751.50 J1.1]]) is required to clearly identify the responsibilities of the wall designer.
 
* Do not use Drycast modular block wall (DMBW-MSE) systems in the following locations:
 
::* Within the splash zone from snow removal operations (assumed to be 15 feet from the edge of the shoulder).
 
::* Where the blocks will be continuously wetted, such as around sources of water.
 
::* Where blocks will be located behind barrier or other obstacles that will trap salt-laden snow from removal operations.
 
* Do not use Drycast modular block wall (DMBW-MSE) systems or Wetcast modular block wall (WMBW-MSE) systems in the following locations:
 
::* For structurally critical applications, such as containing necessary fill around structures.
 
::* In tiered wall systems.
 
* For locations where Drycast modular block wall (DMBW-MSE) systems and Wetcast modular block wall (WMBW-MSE) systems are not desirable, consider coloring agents and/or architectural forms using precast modular panel wall (PMPW-MSE) systems for aesthetic installations.
 
* For slab drain location near MSE Wall, see [[751.10 General Superstructure#General Requirements for Location and Spacing of Slab Drains|EPG 751.10.3.1 Drain Type, Alignment and Spacing]] and [[751.10 General Superstructure#751.10.3.3 General Requirements for Location of Slab Drains|EPG 751.10.3.3 General Requirements for Location of Slab Drains]].


* Roadway runoff should be directed away from running along face of MSE walls used as wing walls on bridge structures.
Use [https://epg.modot.org/index.php/751.50_Standard_Detailing_Notes#G7._Steel_HP_Pile EPG 751.50 Standard Detailing Note G7.3] on plans as required for end bearing piles driven to rock. This requirement shall apply to any type of rock meaning weak to strong rock including stronger shales where HP piling is anticipated to meet refusal. The verification method shown on the plans is only used to verify the nominal axial compressive resistance prior to reaching practical refusal. If the practical refusal criterion is met the field verification method shown on the plans is no longer considered valid.


* Drainage:
For end bearing piles tipped in shale, sandstone, or rock of uncertain strength at any loading where the likelihood of pile damage is increased, the Foundation Investigation Geotechnical Report (FIGR) should give a recommendation for dynamic pile testing (PDA) or no PDA. For most end bearing piles, where a recommendation for field verification is not given in the FIGR, the designer will need to determine whether gates or WEAP is required for the pile driving verification method based on the loading demands on the pile or other factors.


:*Gutter type should be selected at the core team meeting.
For piles bearing on hard rock with MNACR less than 600 kips, FHWA-modified Gates Dynamic Pile Formula should be listed as verification method, and practical refusal criterion should control end of driving criteria. FHWA-modified Gates Dynamic Pile Formula is not considered accurate for pile loading (Minimum Nominal Axial Compressive Resistance) exceeding 600 kips. When pile loading exceeds 600 kips, use wave equation analysis, dynamic testing, or other method. Consideration should be given to using additional piles to reduce the MNACR below 600 kips.  


:* When gutter is required without fencing, use Type A or Type B gutter (for detail, see [https://www.modot.org/media/16880 Std. Plan 609.00]).
Under special circumstances when rock limits or conditions are nonuniform, WEAP should be considered in order to limit pile damage since it requires further scrutiny of the site conditions with the proposed pile driving system.
 
:* When gutter is required with fencing, use Modified Type A or Modified Type B gutter (for detail, see [https://www.modot.org/media/16871 Std. Plan 607.11]).
 
:* When fencing is required without gutter, place in tube and grout behind the MSE wall (for detail, see [https://www.modot.org/bridge-standard-drawings MSE Wall Standard Drawings - MSEW], Fence Post Connection Behind MSE Wall (without gutter).
 
:* Lower backfill longitudinal drainage pipes behind all MSE walls shall be two-6” (Min.) diameter perforated PVC or PE pipe (See Sec 1013) unless larger sizes are required by design which shall be the responsibility of the District Design Division. Show drainage pipe size on plans. Outlet screens and cleanouts should be detailed for any drain pipe (shown on MoDOT MSE wall plans or roadway plans). Lateral non-perforated drain pipes (below leveling pad) are permitted by Standard Specifications and shall be sized by the District Design Division if necessary. Lateral outlet drain pipe sloped at 2% minimum.
 
::* Identify on MSE wall plans or roadway plans drainage pipe point of entry, point of outlet (daylighting), 2% min. drainage slopes in between points to ensure positive flow and additional longitudinal drainage pipes if required to accommodate ground slope changes and lateral drainage pipes if required by design.
 
::* Adjustment in the vertical alignment of the longitudinal drainage pipes from that depicted on the MSE wall standard drawings may be necessary to ensure positive flow out of the drainage system.
   
   
::* Identify on MSE wall plans or roadway plans the outlet ends of pipes which shall be located to prevent clogging or backflow into the drainage system. Outlet screens and cleanouts should be detailed for any drain pipe.
Dynamic Testing is recommended for projects with friction piles where the soil profile is comprised primarily of sand. For bridges where the soil profile is comprised primarily of clays or evenly mixed clays and sands the recommended verification method is WEAP. When WEAP is specified as the pile driving criteria for friction pile, provide standard note E2.28 below the foundation table. For more detailed guidance see [https://www.modot.org/media/54989 SEG 25-001 New Policy for Friction Pile].


:* For more information on drainage, see [[#Drainage at MSE Walls|Drainage at MSE Walls]].
===751.36.5.4 Downdrag and Losses to Geotechnical Resistance due to Scour and Liquefaction===


'''MSE Wall Construction: Pipe Pile Spacers Guidance'''
Downdrag and Losses to Geotechnical Resistance due to Scour and Liquefaction (kips), '''LRFD 10.7.3.6, 10.7.3.7, and AASHTO Guide Specifications for LRFD Seismic Bridge Design (SGS) 6.8.'''


For bridges not longer than 200 feet, pipe pile spacers or pile jackets shall be used at pile locations behind mechanically stabilized earth walls at end bents. Corrugated pipe pile spacers are required when the wall is built prior to driving the piles to protect the wall reinforcement when driving pile for the bridge substructure at end bents(s). Pile spacers or pile jackets may be used when the piles are driven before the wall is built. Pipe pile spacers shall have an inside diameter greater than that of the pile and large enough to avoid damage to the pipe when driving the pile. Use [[751.50 Standard Detailing Notes#E1. Excavation and Fill|EPG 751.50 Standard Detailing Note E1.2a]] on bridge plans.
Downdrag, liquefaction and scour all reduce the available skin friction capacity of piles.  Downdrag <math>\, (DD)</math> is unique because it not only causes a loss of capacity, but also applies a downward force to the piles. This is usually attributed to embankment settlement. However, downdrag can also be caused by a non-liquefied layer overlying a liquefied layer. Review geotechnical report for downdrag and liquefaction information.


For bridges longer than 200 feet, pipe pile spacers are required and the pile spacer shall be oversized to mitigate the effects of bridge thermal movements on the MSE wall. For HP12, HP14, CIP 14” and CIP 16” piles provide 24-inch inside diameter of pile spacer for bridge movement. Minimum pile spacing shall be 5 feet to allow room for compaction of the soil layers. Use [[751.50 Standard Detailing Notes#E1. Excavation and Fill|EPG 751.50 Standard Detailing Note E1.2b]] on bridge plans.
===751.36.5.5 Preliminary Structural Nominal Axial Design Capacity (PNDC) of an individual pile ===


The bottom of the pipe pile spacers shall be placed 5 ft. min. below the bottom of the MSE wall leveling pad. The pipe shall be filled with sand or other approved material after the pile is placed and before driving. Pipe pile spacers shall be accurately located and capped for future pile construction.  
The PNDC equations provided herein assume the piles are continually braced. This assumption is applicable for the portion of piling below ground or confined by solid wall encasement. If designing a pile bent structure, scour exists or liquefaction exists, then the pile shall be checked considering the appropriate unbraced length.


Alternatively, for bridges shorter than or equal to 200 feet, the contractor shall be given the option of driving the piles before construction of the mechanically stabilized earth wall and placing the soil reinforcement and backfill material around the piling. In lieu of pipe pile spacers contractor may place pile jackets on the portion of the piles that will be in the MSE soil reinforced zone prior to placing the select granular backfill material and soil reinforcement. The contractor shall adequately support the piling to ensure that proper pile alignment is maintained during the wall construction. The contractor’s plan for bracing the pile shall be submitted to the engineer for review.
'''Structural Steel HP Piles'''


Piling shall be designed for downdrag (DD) loads due to either method. Oversized pipe pile spacers with sand placed after driving or pile jacket may be considered to mitigate some of the effects of downdrag (DD) loads. Sizing of pipe pile spacers shall account for pile size, thermal movements of the bridge, pile placement plan, and vertical and horizontal placement tolerances.  
:<math>\, PNDC = 0.66^\lambda F_y A_S</math>


When rock is anticipated within the 5 feet zone below the MSE wall leveling pad, prebore into rock and prebore holes shall be sufficiently wide to allow for a minimum 10 feet embedment of pile and pipe pile spacer. When top of rock is anticipated within the 5 to 10 feet zone below the MSE wall leveling pad, prebore into rock to achieve a minimum embedment (pile only) of 10 feet below the bottom of leveling pad. Otherwise, the pipe pile spacer requires a minimum 5 feet embedment below the levelling pad. Consideration shall also be given to oversizing the prebore holes in rock to allow for temperature movements at integral end bents.  
:Since we are assuming the piles are continuously braced, then <math>\,\lambda</math>= 0.  


For bridges not longer than 200 feet, the minimum clearance from the back face of MSE walls to the front face of the end bent beam, also referred to as setback, shall be 4 ft. 6 in. (typ.) unless larger than 18-inch pipe pile spacer required. The 4 ft. 6 in. dimension serves a dual purpose:
:{|
:1) the setback ensures that soil reinforcement is not skewed more than 15° for nut and bolt reinforcement connections to clear an 18-inch inside diameter pipe pile spacers by 6 inches per FHWA-NHI-10-24, Figure 5-17C, while considering vertical and horizontal pile placement tolerances
|<math>\, F_y</math>||is the yield strength of the pile
:2) the setback helps to reduce the forces imparted on the MSE wall from bridge movements that typically are not accounted for in the wall design and cannot be completely isolated using a pipe pile spacer. Increasing the minimum setback shall be considered when larger diameter pile spacers are required or when other types of soil reinforcement connections are anticipated
|-
|<math>\, A_S</math>||is the area of the steel pile
|}


For bridges longer than 200 feet, the minimum setback shall be 5 ft. 6 in. based on the use of 24-inch inside diameter of pipe pile spacers.
'''Welded or Seamless Steel Shell (Pipe) Cast-In-Place Piles (CIP Piles)'''


If interference with soil reinforcement is not a concern and the wall is designed for forces from bridge movement, the following guidance for pipe pile spacers clearance shall be used: pipe pile spacers shall be placed 36 in. clear min. from the back face of MSE wall panels to allow for proper compaction; 12 in. minimum clearance is required between pipe pile spacers and leveling pad and 18 in. minimum clearance is required between leveling pad and pile. For isolated pile (e.g, walls skewed from the bent orientation), the pipe pile spacer may be placed 18 in. clear min. from the back face of MSE wall panels.
:<math>\, PNDC = 0.85 f'_c Ac+F_y A_{st}</math>


'''MSE Wall Plan and Geometrics'''
:{|
|<math>\, F_y</math>||is the yield strength of the pipe pile
|-
|valign="top"|<math>\, A_{st}</math>||is the area of the steel pipe (deducting 12.5 % ASTM tolerance and 1/16 inch corrosion where appropriate.)
|-
|<math>\, f'_c</math>||is the concrete compressive strength at 28 days
|-
|<math>\, Ac</math>|| is the area of the concrete inside the pipe pile
|}


* A plan view shall be drawn showing a baseline or centerline, roadway stations and wall offsets. The plan shall contain enough information to properly locate the wall. The ultimate right of way shall also be shown, unless it is of a significant distance from the wall and will have no effect on the wall design or construction.
:Maximum Load during pile driving = <math>\, 0.90 (f_y A_{st})</math>


* Stations and offsets shall be established between one construction baseline or roadway centerline and a wall control line (baseline). Some wall designs may contain a slight batter, while others are vertical. A wall control line shall be set at the front face of the wall, either along the top or at the base of the wall, whichever is critical to the proposed improvements. For battered walls, in order to allow for batter adjustments of the stepped level pad or variation of the top of the wall, the wall control line (baseline) is to be shown at a fixed elevation. For battered walls, the offset location and elevation of control line shall be indicated. All horizontal breaks in the wall shall be given station-offset points, and walls with curvature shall indicate the station-offsets to the PC and PT of the wall, and the radius, on the plans.  
Welded or Seamless Steel Shell shall be ASTM A252 Modified Grade 3 (50 ksi). ASTM A252 states “the wall thickness at any point shall not be more than 12.5% under the specified nominal wall thickness.” AASHTO recommends deducting 1/16” of the wall thickness due to corrosion (LRFD 5.13.4.5.2). Corrosion need not be considered at construction stage and for drivability analysis and static analysis. For drivability analysis and static analysis deduct 12.5% of specified nominal wall thickness (ASTM A252). For structural design deduct 12.5 % (ASTM A252) and 1/16” for corrosion (LRFD 5.13.4.5.2) from specified nominal wall thickness.


* Any obstacles which could possibly interfere with the soil reinforcement shall be shown. Drainage structures, lighting, or truss pedestals and footings, etc. are to be shown, with station offset to centerline of the obstacle, with obstacle size. Skew angles are shown to indicate the angle between a wall and a pipe or box which runs through the wall.
===751.36.5.6 Preliminary Factored Axial Design Capacity (PFDC) of an Individual Pile ===


* Elevations at the top and bottom of the wall shall be shown at 25 ft. intervals and at any break points in the wall.
:PFDC = Structural Factored Axial Compressive Resistance – Factored Downdrag Load


* Curve data and/or offsets shall be shown at all changes in horizontal alignment. If battered wall systems are used on curved structures, show offsets at 10 ft. (max.) intervals from the baseline.
===751.36.5.7 Design Values for Steel Pile===
====751.36.5.7.1 Integral End Bent Simple Pile Design ====
The following design values may be used for integral end bents where the simple pile design method is applicable per [[751.35 Concrete Pile Cap Integral End Bents#751.35.2.4.2 Pile Design|EPG 751.35.2.4.2 Pile Design]]. These values are not applicable for soils subject to liquefaction or scour where  unbraced lengths may alter the design.  


* Details of any architectural finishes (formliners, concrete coloring, etc.).
=====751.36.5.7.1.1 Design Values for Individual HP Pile=====


* Details of threaded rod connecting the top cap block.
<center>
F<sub>y</sub> = 50 ksi. End Bearing Piles (HP piles) anticipated to be driven to rock.
{|border="1" style="text-align:center;" cellpadding="5" align="center"  cellspacing="0"
!Pile Size!!A<sub>s</sub><br/>Area,<br/>sq. in.!!Structural<br/>Nominal<br/>Axial<br/>Compressive<br/>Resistance<br/>PNDC<sup>1,2</sup>,<br/>kips!!Φ<sub>c</sub><br/>Structural<br/>Resistance<br/>Factor<sup>4,5</sup>,<br/>LRFD 6.5.4.2!!Structural<br/>Factored<br/>Axial<br/>Compressive<br/>Resistance<sup>2,3,4</sup>,<br/>kips!!0.9*ϕ<sub>da</sub>*F<sub>y</sub><br/>Maximum<br/>Nominal<br/>Driving<br/>Stress,<br/>LRFD 10.7.8,<br/>ksi
|-
|HP 12x53|| 15.5|| 775|| 0.35|| 271|| 45.00
|-
|HP 14x73|| 21.4|| 1070|| 0.35|| 375|| 45.00
|-
|colspan="6" align="left"|'''<sup>1</sup>''' Structural Nominal Axial Compressive Resistance for fully embedded piles only. <br/><br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Minimum Nominal Axial Compressive Resistance  =  Required nominal driving resistance, R<sub>ndr</sub><br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = (Maximum factored axial loads / ϕ<sub>dyn</sub>) ≤ Structural nominal axial compressive resistance, PNDC &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;LRFD 10.5.5.2.3<br/><br/>
'''<sup>2</sup>''' Axial Compressive Resistance values shown above shall be reduced when downdrag is considered.
<br/><br/>'''<sup>3</sup>''' Maximum factored axial load per pile  ≤  Structural factored axial compressive resistance.
<br/><br/>'''<sup>4</sup>''' Values are applicable for Strength Limit States.
<br/><br/>'''<sup>5</sup>''' Use (Φ<sub>c</sub>) = 0.35 instead of 0.5 for structural resistance factor (LRFD 6.5.4.2)
<br/><br/><br/>'''Notes:
<br/><br/>ϕ<sub>dyn</sub> = Resistance factor of the dynamic method to be used to estimate nominal pile resistance during pile installation.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; LRFD Table 10.5.5.2.3-1
<br/><br/>For more information about selecting pile driving verification methods refer to [[751.36_Driven_Piles#751.36.5.3_Geotechnical_Resistance_Factor_.28.CF.95stat.29_and_Driving_Resistance_Factor_.28.CF.95dyn.29|EPG 751.36.5.3 Geotechnical Resistance Factor (ϕ<sub>stat</sub>) and Driving Resistance Factor (ϕ<sub>dyn</sub>)]]. 
<br/><br/>Drivability analysis shall be performed for all HP piles using Delmag D19-42.  Do not show minimum hammer energy on plans.
<br/><br/>Check drivability for all HP Pile in accordance with [[#751.36.5.11 Check Pile Drivability|EPG 751.36.5.11]]
<br/><br/>For additional design requirements, see [[#751.36.5.1 Design Procedure Outline|EPG 751.36.5.1]].
|}
</center>


* Estimated quantities, total sq. ft. of mechanically stabilized earth systems.
=====751.36.5.7.1.2 Design Values for Individual Cast-In-Place (CIP) Pile=====


* Proposed grade and theoretical top of leveling pad elevation shall be shown in constant slope. Slope line shall be adjusted per project. Top of wall or coping elevation and stationing shall be shown in the developed elevation per project. If leveling pad is anticipated to encounter rock, then contact the Geotechnical Section for leveling pad minimum embedment requirements.
<center>
Modified Grade 3 F<sub>y</sub> = 50 ksi; F'<sub>c</sub> = 4 ksi; Structural Axial Compressive Resistance Factor, (Φ<sub>c</sub>)<sup>1,3</sup> = 0.35
{|border="1" style="text-align:center;" cellpadding="5" align="center" cellspacing="0"
|-
! colspan="8" | Unfilled Pipe For Axial Analysis<sup>2</sup>
|-
! Pile Outside Diameter O.D., in. !! Pile Inside Diameter I.D., in. !! Minimum Wall Thickness, in. !! Reduced Wall thick. for Fabrication (ASTM A252), in. !! A<sub>s</sub>,<sup>4</sup><br/>Area<br/>of<br/>Steel<br/>Pipe,<br/>sq. in. !! Structural<br/>Nominal<br/>Axial<br/>Compressive<br/>Resistance<br/>P<sub>n</sub><sup>5,6,7</sup>,<br/>kips !! Structural<br/>Factored Axial<br/>Compressive<br/>Resistance<sup>1,7,8</sup>,<br/>kips !! 0.9*ϕ<sub>da</sub>*F<sub>y</sub>*A<sub>s</sub><br/>Maximum<br/>Nominal<br/>Driving<br/>Resistance<sup>6</sup>,<br/>LRFD 10.7.8,<br/>kips
|-
| rowspan="2" | 14 || 13 || 0.5 || 0.44 || 18.47 || 923 || 323 || 831
|-
| 12.75 || 0.625<sup>9</sup> || 0.55 || 22.84 || 1142 || 400 || 1028
|-
| rowspan="2" | 16 || 15 || 0.5 || 0.44 || 21.22 || 1061 || 371 || 955
|-
| 14.75 || 0.625<sup>9</sup> || 0.55 || 26.28 || 1314 || 460 || 1183
|-
| rowspan="2" | 20 || 19 || 0.5 || 0.44 || 26.72 || 1336 || 468 || 1202
|-
| 18.75 || 0.625 || 0.55 || 33.15 || 1658 || 580 || 1492
|-
| rowspan="3" | 24 || 23 || 0.5 || 0.44 || 32.21 || 1611 || 564 || 1450
|-
| 22.75 || 0.625 || 0.55 || 40.03 || 2001 || 700 || 1801
|-
| 22.5 || 0.75 || 0.66 || 47.74 || 2387 || 835 || 2148
|-
| colspan="8" align="left" |
'''<sup>1</sup>'''Values are applicable for Strength Limit States.


'''MSE Wall Cross Sections'''
'''<sup>2</sup>''' Use to determine preliminary number of pile and pile size. For piles predominantly embedded and tipped in cohesionless soils the maximum loads provided in [[#751.36.5.10 Pile Nominal Axial Compressive Resistance|EPG 751.36.5.10]] will control.


* A typical wall section for general information is shown.
'''<sup>3</sup>''' Use (Φ<sub>c</sub>) = 0.35 instead of 0.6 for structural axial compressive resistance factor (LRFD 6.5.4.2). Since ϕ<sub>dyn</sub> >> Φ<sub>c</sub> the maximum nominal driving resistance may not control.


* Additional sections are drawn for any special criteria. The front face of the wall is drawn vertical, regardless of the wall type.
'''<sup>4</sup>''' Corrosion NOT considered at construction stage and for drivability analysis and static analysis. For drivability analysis and static analysis use reduced pipe nominal wall thickness, 12.5%, for fabrication (ASTM A252).


* Any fencing and barrier or railing are shown.
'''<sup>5</sup>''' Structural Nominal Axial compressive resistance for fully embedded piles only.


* Barrier if needed are shown on the cross section. Barriers are attached to the roadway or shoulder pavement, not to the MSE wall. Standard barriers are placed along wall faces when traffic has access to the front face of the wall over shoulders of paved areas.
'''<sup>6</sup>''' Minimum Nominal Axial Compressive Resistance = Required nominal driving resistance, R<sub>ndr</sub>


<div id="Drainage at MSE Walls"></div>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = Maximum factored axial loads / ϕ<sub>dyn</sub> ≤ Structural nominal axial compressive resistance, P<sub>n</sub> and &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; LRFD 10.5.5.2.3
'''Drainage at MSE Walls'''


*'''Drainage Before MSE Wall'''
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ≤ Maximum nominal driving resistance.


:Drainage is not allowed to be discharged within 10 ft. from front of MSE wall in order to protect wall embedment, prevent erosion and foundation undermining, and maintain soil strength and stability.
'''<sup>7</sup>''' Axial Compressive Resistance values shown above shall be reduced when downdrag is considered.


*'''Drainage Behind MSE Wall'''
'''<sup>8</sup>''' Maximum factored axial load per pile ≤ Structural factored axial compressive resistance.


::'''Internal (Subsurface) Drainage'''
'''<sup>9</sup>''' 5/8” wall thickness is less commonly available than the smaller wall thicknesses of pipe pile.


::Groundwater and infiltrating surface waters are drained from behind the MSE wall through joints between the face panels or blocks (i.e. wall joints) and two-6 in. (min.) diameter pipes located at the base of the wall and at the basal interface between the reinforced backfill and the retained backfill.
'''Notes: '''


::Excessive subsurface draining can lead to increased risk of backfill erosion/washout through the wall joints and erosion at the bottom of walls and at wall terminal ends. Excessive water build-up caused by inadequate drainage at the bottom of the wall can lead to decreased soil strength and wall instability. Bridge underdrainage (vertical drains at end bents and at approach slabs) can exacerbate the problem.
Drivability analysis shall be performed for all CIP piles (unfilled pipe) using Delmag D19-42. Do not show minimum hammer energy on plans.


::Subsurface drainage pipes should be designed and sized appropriately to carry anticipated groundwater, incidental surface run-off that is not collected otherwise including possible effects of drainage created by an unexpected rupture of any roadway drainage conveyance or storage as an example.
Check drivability for all CIP Pile in accordance with [[#751.36.5.11 Check Pile Drivability|EPG 751.36.5.11]].


::'''External (Surface) Drainage'''
Require dynamic pile testing for field verification for all CIP piles on the plans. <br/>ϕ<sub>dyn</sub> = 0.65 = Dynamic Testing resistance factor to be used to estimate nominal pile resistance during pile installation. This value may be increased if static load testing is specified per LRFD Table 10.5.5.2.3-1.


::External drainage considerations deal with collecting water that could flow externally over and/or around the wall surface taxing the internal drainage and/or creating external erosion issues. It can also infiltrate the reinforced and retained backfill areas behind the MSE wall.
For additional design requirements, see [[#751.36.5.1 Design Procedure Outline|EPG 751.36.5.1]].
 
::Diverting water flow away from the reinforced soil structure is important. Roadway drainage should be collected in accordance with roadway drainage guidelines and bridge deck drainage should be collected similarly.
 
*'''Guidance'''
 
:ALL MSE WALLS
 
:1. Appropriate measures to prevent surface water infiltration into MSE wall backfill should be included in the design and detail layout for all MSE walls and shown on the roadway plans.
 
:2. Gutters behind MSE walls are required for flat or positive sloping backfills to prevent concentrated infiltration behind the wall facing regardless of when top of backfill is paved or unpaved. This avoids pocket erosion behind facing and protection of nearest-surface wall connections which are vulnerable to corrosion and deterioration. Drainage swales lined with concrete, paved or precast gutter can be used to collect and discharge surface water to an eventual point away from the wall. If rock is used, use impermeable geotextile under rock and align top of gutter to bottom of rock to drain. (For negative sloping backfills away from top of wall, use of gutters is not required.)
 
:District Design Division shall verify the size of the two-6 in. (min.) diameter lower perforated MSE wall drain pipes and where piping will daylight at ends of MSE wall or increase the diameters accordingly.  This should be part of the preliminary design of the MSE wall. (This shall include when lateral pipes are required and where lateral drain pipes will daylight/discharge).
:BRIDGE ABUTMENTS WITH MSE WALLS
 
:Areas of concern: bridge deck drainage, approach slab drainage, approach roadway drainage, bridge underdrainage:  vertical drains at end bents and approach slab underdrainage, showing drainage details on the roadway and MSE wall plans
 
:3. Bridge slab drain design shall be in accordance with [[751.10 General Superstructure#751.10.3 Bridge Deck Drainage - Slab Drains |EPG 751.10.3 Bridge Deck Drainage – Slab Drains]] unless as modified below.
 
:4. Coordination is required between the Bridge Division and District Design Division on drainage design and details to be shown on the MSE wall and roadway plans.
 
:5. Bridge deck, approach slab and roadway drainage shall not be allowed to be discharged to MSE wall backfill area or within 10 feet from front of MSE wall.
::*(Recommended) Use of a major bridge approach slab and approach pavement is ideal because bridge deck, approach slab and roadway drainage are directed using curbs and collected in drain basins for discharge that protect MSE wall backfill. For bridges not on a major roadway, consideration should be given to requiring a concrete bridge approach slab and pavement incorporating these same design elements (asphalt is permeable).
 
::*(Less Recommended) Use of conduit and gutters:
 
:::* Conduit: Drain away from bridge and bury conduit daylighting to natural ground or roadway drainage ditch at an eventual point beyond the limits of the wall. Use expansion fittings to allow for bridge movement and consider placing conduit to front of MSE wall and discharging more than 10 feet from front of wall or using lower drain pipes to intercept slab drainage conduit running through backfill.
 
:::* Conduit and Gutters: Drain away from bridge using conduit and 90° elbow (or 45° bend) for smoothly directing drainage flow into gutters and that may be attached to inside of gutters to continue along downward sloping gutters along back of MSE wall to discharge to sewer or to natural drainage system, or to eventual point beyond the limits of the wall.  Allow for independent bridge and wall movements by using expansion fittings where needed. See [[751.10 General Superstructure#751.10.3.1 Type, Alignment and Spacing|EPG 751.10.3.1 Type, Alignment and Spacing]] and [[751.10 General Superstructure#751.10.3.3 General Requirements for Location of Slab Drains|EPG 751.10.3.3 General Requirements for Location of Slab Drains]].
 
:6. Vertical drains at end bents and approach slab underdrainage should be intercepted to drain away from bridge end and MSE wall.
 
:7. Discharging deck drainage using many slab drains would seem to reduce the volume of bridge end drainage over MSE walls.
 
:8. Drain flumes at bridge abutments with MSE walls do not reduce infiltration at MSE wall backfill areas and are not recommended.
 
:DISTRICT DESIGN DIVISION MSE WALLS
 
:Areas of concern: roadway or pavement drainage, MSE wall drainage, showing drainage details on the roadway and MSE wall plans.
 
:9. For long MSE walls, where lower perforated drain pipe slope become excessive, non-perforated lateral drain pipes, permitted by Standard Specifications, shall be designed to intercept them and go underneath the concrete leveling pad with a 2% minimum slope. Lateral drain pipes shall daylight/discharge at least 10 ft. from front of MSE wall. Screens should be installed and maintained on drain pipe outlets.
 
:10. Roadway and pavement drainage shall not be allowed to be discharged to MSE wall backfill area or within 10 feet from front of MSE wall.
 
:11. For district design MSE walls, use roadway or pavement drainage collection pipes to transport and discharge to an eventual point outside the limits of the wall.
 
:Example: Showing drain pipe details on the MSE wall plans.
 
<gallery mode=packed widths=300px heights=300px>
File:751.24.2.1_elev_drain_pipe-01.png| <big>'''ELEVATION SHOWING DRAIN PIPE'''</big>
File:751.24.2.1_elev_drain_pipe_alt-01.png| <big>'''Alternate option'''</big>
</gallery>
<gallery mode=packed widths=400px heights=400px>
File:751.24.2.1_sec_A-A-02.png| <big>'''Section A-A'''</big>
</gallery>
{| style="text-align: left; margin-left: auto; margin-right: auto;"
|
Notes:</br>
(1) To be designed by District Design Division.</br>
(2) To be designed by District Design Division if needed. Provide non-perforated lateral drain pipe under leveling pad at 2% minimum slope. (Show on plans).</br>
(3) Discharge to drainage system or daylight screened outlet at least 10 feet away from end of wall (typ.). (Skew in the direction of flow as appropriate).</br>
(4) Discharge to drainage system or daylight screened outlet at least 10 feet away from front face of wall (typ.). (Skew in the direction of flow as appropriate).</br>
(5) Minimum backfill cover = Max(15”, 1.5 x diameter of drain pipe).</br>
|}
|}
</center>


=== E1. Excavation and Fill ===
====751.36.5.7.2 General Pile Design====


'''(E1.1) Use when specified on the Design Layout.'''
The following design values are recommended for general use where the simple pile design method is not applicable per [[751.35 Concrete Pile Cap Integral End Bents#751.35.2.4.2 Pile Design|EPG 751.35.2.4.2 Pile Design]]. These values are not applicable for soils subject to liquefaction or scour where unbraced lengths may alter the design.
:Existing roadway fill under the ends of the bridge shall be removed as shown. Removal of existing roadway fill will be considered completely covered by the contract unit price for roadway excavation.


'''Use one of the following two notes where MSE walls support abutment fill.'''
=====751.36.5.7.2.1 Design Values for Individual HP Pile=====
 
'''(E1.2a) <font color="purple">[MS Cell]</font color="purple">  Use when pipe pile spacers are shown on plan details and bridge is 200 feet long or shorter. Add “See special provisions” to the pipe pile spacer callout  and add table near the callout.'''
 
See special provisions.


<center>
<center>
{|border="1" style="text-align:center;" cellpadding="5" cellspacing="0"
F<sub>y</sub> = 50 ksi. End Bearing Piles (HP piles) anticipated to be driven to rock.
{|border="1" style="text-align:center;" cellpadding="5" align="center"  cellspacing="0"
!Pile Size!!A<sub>s</sub><br/>Area,<br/>sq. in.!!Structural<br/>Nominal<br/>Axial<br/>Compressive<br/>Resistance<br/>PNDC<sup>1,2</sup>,<br/>kips!!Φ<sub>c</sub><br/>Structural<br/>Resistance<br/>Factor<sup>4</sup>,<br/>LRFD 6.5.4.2!!Structural<br/>Factored<br/>Axial<br/>Compressive<br/>Resistance<sup>2,3,4</sup>,<br/>kips!!0.9*ϕ<sub>da</sub>*F<sub>y</sub><br/>Maximum<br/>Nominal<br/>Driving<br/>Stress,<br/>LRFD 10.7.8,<br/>ksi
|-
|-
!style="background:#BEBEBE" width="200"| Pile Encasement !!style="background:#BEBEBE"|Option Used<br/>(√)
|HP 12x53|| 15.5|| 775|| 0.5|| 388|| 45.00
|-
|-
|Pipe Pile Spacer ||
|HP 14x73|| 21.4|| 1070|| 0.5|| 535|| 45.00
|-
|-
|Pile Jacket ||
|colspan="6" align="left"|'''<sup>1</sup>''' Structural Nominal Axial Compressive Resistance for fully embedded piles only. Structural Nominal Axial Compressive Resistance for unsupported piles shall be determined in accordance with LRFD 10.7.3.13.1. (i.e., intermediate pile cap bent).<br/><br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Minimum Nominal Axial Compressive Resistance  =  Required nominal driving resistance, R<sub>ndr</sub><br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = (Maximum factored axial loads / ϕ<sub>dyn</sub>) ≤ Structural nominal axial compressive resistance, PNDC &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;LRFD 10.5.5.2.3<br/><br/>
'''<sup>2</sup>''' Axial Compressive Resistance values shown above shall be reduced when downdrag is considered.
<br/><br/>'''<sup>3</sup>''' Maximum factored axial load per pile  ≤  Structural factored axial compressive resistance.
<br/><br/>'''<sup>4</sup>''' Values are applicable for Strength Limit States.  Modify value for other Limit States.
<br/><br/><br/>'''Notes:
<br/><br/>ϕ<sub>dyn</sub> = Resistance factor of the dynamic method to be used to estimate nominal pile resistance during pile installation.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; LRFD Table 10.5.5.2.3-1
<br/><br/>For more information about selecting pile driving verification methods refer to [[751.36_Driven_Piles#751.36.5.3_Geotechnical_Resistance_Factor_.28.CF.95stat.29_and_Driving_Resistance_Factor_.28.CF.95dyn.29|EPG 751.36.5.3 Geotechnical Resistance Factor (ϕ<sub>stat</sub>) and Driving Resistance Factor (ϕ<sub>dyn</sub>)]].
<br/><br/>Drivability analysis shall be performed for all HP piles using Delmag D19-42. Do not show minimum hammer energy on plans.
<br/><br/>Check drivability for all HP Pile in accordance with [[#751.36.5.11 Check Pile Drivability|EPG 751.36.5.11]]
<br/><br/>For additional design requirements, see [[#751.36.5.1 Design Procedure Outline|EPG 751.36.5.1]].
|}
|}
</center>
</center>
MoDOT Construction personnel will indicate the pile encasement used.
'''(E1.2b) Use note when pipe pile spacers are shown on plan details for HP12, HP14, CIP 14” and CIP 16” piles and bridge is longer than 200 feet. For larger CIP pile size modify following note and use minimum 6” larger pipe pile spacer diameter than CIP pile.'''


The pipe pile spacers shall have an inside diameter equal to <u>24</u> inches.
=====751.36.5.7.2.2 Design Values for Individual Cast-In-Place (CIP) Pile=====


'''(E1.4) Use for fill at pile cap end bents. Use the first underlined portion when MSE walls are present. Use <u>approach</u> for semi-deep abutments.'''
<center>
:Roadway fill<u>, exclusive of Select Granular Backfill for Structural Systems,</u> shall be completed to the final roadway section and up to the elevation of the bottom of the concrete <u>approach</u> beam within the limits of the structure and for not less than 25 feet in back of the fill face of the end bents before any piles are driven for any bents falling within the embankment section.
Modified Grade 3 F<sub>y</sub> = 50 ksi; F'<sub>c</sub> = 4 ksi; Structural Resistance Factor, (Φ<sub>c</sub>)<sup>'''1'''</sup> = 0.6
 
{|border="1" style="text-align:center;" cellpadding="5" align="center" cellspacing="0"
----
! colspan="8" | Unfilled Pipe For Axial Analysis<sup>2</sup> !! colspan="5" | Concrete Filled Pipe For Flexural Analysis<sup>3</sup>  
 
|-
 
! Pile Outside Diameter O.D., in. !! Pile Inside Diameter I.D., in. !! Minimum Wall Thickness, in. !! Reduced Wall thick. for Fabrication (ASTM A252), in. !! A<sub>s</sub>,<sup>4</sup> Area of Steel Pipe, sq. in. !! Structural Nominal Axial Compressive Resistance, P<sub>n</sub><sup>5,6,7</sup>, kips !! Structural Factored Axial Compressive Resistance<sup>1,7,8</sup>, kips !! 0.9*ϕ<sub>da</sub>*F<sub>y</sub>*A<sub>s</sub> Maximum<br/>Nominal<br/>Driving<br/>Resistance<sup>5,6</sup>, LRFD 10.7.8, kips !! Reduced Wall Thick. for Corrosion (1/16"), LRFD 5.13.4.5.2, in. !! A<sub>st</sub>,<sup>9</sup> Net Area of Steel Pipe, sq. in. !! A<sub>c</sub> Concrete Area, sq. in. !! Structural Nominal Axial Compressive Resistance PNDC<sup>5,7,10</sup>, kips !! Structural Factored Axial Compressive Resistance<sup>1,7,10</sup>, kips
='''REVISION REQUEST 4034'''=
|-
 
| rowspan="2" | 14 || 13 || 0.5 || 0.44 || 18.47 || 923 || 554 || 831 || 0.375 || 15.76 || 133 || 1239 || 743
<big><big>'''<font color= red>!!!  Only replace first part of 751.9.1 up to 751.9.1.1  !!!</font color>'''</big></big>
|-
 
| 12.75 || 0.625<sup>'''11'''</sup> || 0.55 || 22.84 || 1142 || 685 || 1028 || 0.484 || 20.14 || 128 || 1441 || 865
==751.9.1 Seismic Analysis and Design Specifications==
|-
<div style="float: left; margin-top: 5px; margin: 15px; width:255px; background-color: #f8f9fa; padding: 0.3em; border: 1px solid #a2a9b1; text-align:left;">
| rowspan="2" | 16 || 15 || 0.5 || 0.44 || 21.22 || 1061 || 637 || 955 || 0.375 || 18.11 || 177 || 1506 || 904
'''<u><center>Additional Information</center></u>'''
|-
* [https://epg.modot.org/forms/general_files/BR/Bridge_Seismic_Design_Flowchart.pdf Bridge Seismic Design Flowchart]
| 14.75 || 0.625<sup>'''11'''</sup> || 0.55 || 26.28 || 1314 || 788 || 1183 || 0.484 || 23.18 || 171 || 1740 || 1044
</div>
|-
All new or replacement bridges on the state system shall include seismic design and/or detailing to resist an expected seismic event per the [https://epg.modot.org/forms/general_files/BR/Bridge_Seismic_Design_Flowchart.pdf Bridge Seismic Design Flowchart]. For example, for a bridge in Seismic Design Categories A, B, C or D, complete seismic analysis or seismic detailing only may be determined as per “[https://epg.modot.org/forms/general_files/BR/Bridge_Seismic_Design_Flowchart.pdf Bridge Seismic Design Flowchart]”.
| rowspan="2" | 20 || 19 || 0.5 || 0.44 || 26.72 || 1336 || 801 || 1202 || 0.375 || 22.83 || 284 || 2105 || 1263
 
|-
Missouri is divided into four Seismic Design Categories. Most of the state is SDC A which requires minimal seismic design and/or detailing in accordance with SGS (Seismic Zone 1 of LRFD) and “[https://epg.modot.org/forms/general_files/BR/Bridge_Seismic_Design_Flowchart.pdf Bridge Seismic Design Flowchart]”. The other seismic design categories will require a greater amount of seismic design and/or detailing.
| 18.75 || 0.625 || 0.55 || 33.15 || 1658 || 995 || 1492 || 0.484 || 29.27 || 276 || 2402 || 1441
 
|-
For seismic detailing only:
| rowspan="3" | 24 || 23 || 0.5 || 0.44 || 32.21 || 1611 || 966 || 1450 || 0.375 || 27.54 || 415 || 2790 || 1674
 
|-
When A<sub>S</sub> is greater than 0.75 then use A<sub>S</sub> = 0.75 for abutment design where required per “[https://epg.modot.org/forms/general_files/BR/Bridge_Seismic_Design_Flowchart.pdf Bridge Seismic Design Flowchart]” and [https://www.modot.org/media/47036 SEG 24-01]
| 22.75 || 0.625 || 0.55 || 40.03 || 2001 || 1201 || 1801 || 0.484 || 35.36 || 406 || 3150 || 1890
 
|-
For complete seismic analysis:
| 22.5 || 0.75 || 0.66 || 47.74 || 2387 || 1432 || 2148 || 0.594 || 43.08 || 398 || 3506 || 2103
 
When A<sub>S</sub> is greater than 0.75 then use A<sub>S</sub> = 0.75 at zero second for seismic analysis and response spectrum curve. See [https://epg.modot.org/forms/general_files/BR/Example-1_SDC_Response_Spectra.docx Example 1_SDC_Response_Spectra]. The other data points on the response spectrum curve shall not be modified.
 
<div style="float: left; margin-top: 5px; margin: 15px; width:255px; background-color: #f8f9fa; padding: 0.3em; border: 1px solid #a2a9b1; text-align:left;">
'''<u><center>Additional Information</center></u>'''
* [https://epg.modot.org/forms/general_files/BR/Bridge_Seismic_Retrofit_Flowchart.pdf Bridge Seismic Retrofit Flowchart]
</div>
 
When existing bridges are identified as needing repairs or maintenance, a decision on whether to include seismic retrofitting in the scope of the project shall be determined per the “[https://epg.modot.org/forms/general_files/BR/Bridge_Seismic_Retrofit_Flowchart.pdf Bridge Seismic Retrofit Flowchart]”, the extent of the rehabilitation work and the expected life of the bridge after the work. For example, if the bridge needs painting or deck patching, no retrofitting is recommended. However, redecking or widening the bridge indicates that MoDOT is planning to keep the bridge in the state system with an expected life of at least 30 more years. In these instances, the project core team should consider cost effective methods of retrofitting the existing bridge. Superstructure replacement requires a good substructure and the core team shall decide whether there is sufficient seismic capacity. Follow the design procedures for new or replacement bridges in forming logical comparisons and assessing risk in a rational determination of the scope of a superstructure replacement project specific to the substructure. For example, based on SPC and route, retrofit of the substructure could include seismic detailing only or a complete seismic analysis may be required determine sufficient seismic capacity. Economic analysis should be considered as part of the decision to re-use and retrofit, or re-build. Where practical, make end bents integral and eliminate expansion joints. Seismic isolation systems shall conform to AASHTO Guide Specifications for Seismic Isolation Design 4th Ed. 2023.
 
Bridge seismic retrofit for widenings shall be in accordance with [https://epg.modot.org/forms/general_files/BR/Bridge_Seismic_Retrofit_Flowchart.pdf Bridge Seismic Retrofit Flowchart]. Seismic details should only be considered for widenings where they can be practically implemented and where they can be uniformly implemented as not to create significant stress redistribution in the structure. When a complete seismic analysis is required for widenings the existing structure shall be retrofitted and the new structural elements shall be detailed to resist seismic demand.  
 
* '''Seismic Details for Widening (one side):''' When widening the bridge in one direction there is not a significant benefit, and it could be detrimental, to strengthen a new wing or column while ignoring the existing structure. It may be practical to use FRP wrap to retrofit the existing columns to provide a similar level of service to a new column with seismic details, but this will likely require design computations to verify (see below). For SDC C and D, seismic details typically require a T-joint detail in the beam cap and footing, but t-joint details shall be ignored if the existing beam cap is not retrofitted. For abutments it is not practical to dig up an existing wing solely to match the new wing design so the abutment need not be designed for mass inertial forces. SPM, SLE or owner’s representative approval is required to determine the appropriate level of seismic detail implementation.
* '''Seismic Details for Widening (both sides):''' When widening in both directions the wings shall be designed to resist the mass inertial forces. Seismic details shall be added to the new columns in SDC B only if the existing columns can be retrofitted with FRP wrap to provide a similar level of service as discussed below. SDC C and D bridges may be detailed and retrofitted similar to SDC B since retrofitting the beam cap or footing is likely not practical.
* '''Seismic Details for Widening (FRP wrap)''': Carbon or glass fiber reinforced polymer (FRP) composite wrap should be considered to strengthen the factored axial resistance of existing columns. There are limitations to the existing and achievable column factored axial resistance with FRP wrap. The goal of the FRP wrap is to increase the factored axial resistance of the existing column to be not less than the factored axial resistance of the new column with seismic details. If an existing column cannot be retrofitted with FRP wrap to match the factored axial resistance of a new column with seismic details at the same bent then seismic details shall be ignored for all columns in the bridge substructure. See AASHTO Guide Spec for Design of Bonded FRP Systems for Repair and Strengthening of Concrete Bridge Elements, March 2023, 2nd Ed., Appendix A, Example 6 for an example for increasing column factored axial resistance with FRP wrap. Use [[751.50_Standard_Detailing_Notes#I5._Fiber_Reinforced_Polymer_(FRP)_Wrap_–_Intermediate_Bent_Column_Strengthening_for_Seismic_Details_for_Widening._Report_following_notes_on_Intermediate_bent_plan_details.|EPG 751.50 Standard Detailing Notes I5]] on plans to report factored axial resistance of existing column and new column. The flexural resistance of the column is also increased with FRP wrap, but it may not be practical to match the flexural resistance of a new column using existing longitudinal steel. For additional references, see [[751.40_LFD_Widening_and_Repair#751.40.3.2_Bent_Cap_Shear_Strengthening_using_FRP_Wrap|EPG 751.40.3.2 Bent Cap Shear Strengthening using FRP Wrap]].
 
 
 
 
 
===751.40.3.2 Bent Cap Shear Strengthening using FRP Wrap===
 
{| class="wikitable" style="margin: 0 auto; text-align: center"
|+
| style="background:#BEBEBE" | '''[https://www.modot.org/bridge-standard-drawings Bridge Standard Drawings]'''
|-
|-
| Rehabilitation, Surfacing & Widening; Fiber Reinf. Polymer (FRP) Wrap for Bent Cap Strengthening [RHB08]
| colspan="13" align="left" |
|}
'''<sup>1</sup>''' Values are applicable for Strength Limit States. Modify value for other Limit States.


Fiber Reinforced Polymer (FRP) wrap may be used for Bent Cap Shear Strengthening. FRP wrap may also be used for seismic retrofit of existing columns, but that procedure is not discussed herein (see [[751.9_Bridge_Seismic_Design#751.9.1_Seismic_Analysis_and_Design_Specifications|EPG 751.9.1 Seismic Analysis and Design Specifications]]).
'''<sup>2</sup>''' Use to determine preliminary number of pile and pile size. For piles predominantly embedded and tipped in cohesionless soils the maximum loads provided in [[#751.36.5.10 Pile Nominal Axial Compressive Resistance|EPG 751.36.5.10]] will control.


'''When to strengthen:''' When increased shear loading on an existing bent cap is required and a structural analysis shows insufficient bent cap shear resistance, bent cap shear strengthening is an option.  An example of when strengthening a bent cap may be required:  removing existing girder hinges and making girders continuous will draw significantly more force to the adjacent bent. An example of when strengthening a bent cap is not required:  redecking a bridge  where analysis shows that the existing bent cap cannot meet capacity for an HS20 truck loading, and the new deck is similar to the old deck and the existing beam is in good shape.
'''<sup>3</sup>''' Pipes placed in prebored holes in rock can use filled pipe capacity for axial plus flexural resistance. Therefore, number of piles should be based on this capacity assuming rock is infinitely more stiff. This recognizes that pile driving is not a concern.


'''How to strengthen:''' Using FRP systems for shear strengthening follows from the guidelines set forth in ''NCHRP Report 678, Design of FRP System for Strengthening Concrete Girders in Shear''. The method of strengthening, using either discrete strips or continuous sheets, is made optional for the contractor in accordance with ''NCHRP Report 678''.  A Bridge Standard Drawing and Bridge Special Provision have been prepared for including this work on jobs. They can be revised to specify a preferred method of strengthening if desired, strips or continuous sheet.
'''<sup>4</sup>''' Corrosion NOT considered at construction stage and for drivability analysis and static analysis. For drivability analysis and static analysis use reduced pipe nominal wall thickness, 12.5%, for fabrication (ASTM A252).


'''What condition of existing bent cap required for strengthening:''' If a cap is in poor shape where replacement should be considered, FRP should not be used. Otherwise, the cap beam can be repaired before applying FRP. Perform a minimum load check using (1.1DL + 0.75(LL+I))'''*''' on the existing cap beam to prevent catastrophic failure of the beam if the FRP fails (''ACI 440.2R, Guide for the Design and Construction of Externally Bonded FRP, Sections 9.2 and 9.3.3''). If the factored shear resistance of the cap beam is insufficient for meeting the factored minimum load check, then FRP strengthening should not be used.
'''<sup>5</sup>''' Structural Nominal Axial compressive resistance for fully embedded piles only. Value in table is a raw number and is the value used to determine the factored resistance. Structural Nominal Axial Compressive Resistance for unsupported piles shall be determined in accordance with LRFD 10.7.3.13.1. (i.e. Intermediate pile cap bent).  
   
:: '''*''' ACI 440.2R: ''Guide for the Design and Construction of Externally Bonded FRP''


'''Design force (net shear strength loading):''' Strengthening a bent cap requires determining the net factored shear loading that the cap beam must carry in excess of its unstrengthened factored shear capacity, or resistance. The FRP system is then designed by the manufacturer to meet this net factored shear load, or design force.  The design force for a bent cap strengthening is calculated considering AASHTO LFD where the factored load is the standard Load Factor Group I load case.  To determine design force that the FRP must carry alone, the factored strength of the bent cap, which is 0.85 x nominal strength according to LFD design, is subtracted out to give the net factored shear load that the FRP must resist by itself.  ''NCHRP Report 678'' is referenced in the special provisions as guidelines for the contractor and the manufacturer to follow.  The report and its examples use AASHTO LRFD.  <u>Regardless, the load factor case is given and it is left to the manufacturer to provide for a satisfactory factor of safety based on their FRP system.</u>
'''<sup>6</sup>''' Minimum Nominal Axial Compressive Resistance = Required nominal driving resistance, R<sub>ndr</sub>


Other References:
&nbsp; &nbsp; &nbsp; = Maximum factored axial loads / ϕ<sub>dyn</sub> ≤ Structural nominal axial compressive resistance, P<sub>n</sub> and &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; LRFD 10.5.5.2.3
:: '''*''' ACI 201.1R: ''Guide for Making a Condition Survey of Concrete in Service''
:: '''*''' ACI 224.1R: ''Causes, Evaluation, and Repair of Cracks in Concrete''
:: '''*''' ACI 364.1R-94: ''Guide for Evaluation of Concrete Structures Prior to Rehabilitation''
:: '''*''' ACI 440.2R-08: ''Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures''
:: '''*''' ACI 503R: ''Use of Epoxy Compounds with Concrete''
:: '''*''' ACI 546R: ''Concrete Repair Guide''
:: '''*''' International Concrete Repair Institute (ICI) ICI 03730: ''Guide for Surface Preparation for the Repair of Deteriorated Concrete Resulting from Reinforcing Steel Corrosion''
:: '''*''' International Concrete Repair Institute (ICI) ICI 03733: ''Guide for Selecting and Specifying Materials for Repairs of Concrete Surfaces''
:: '''*''' NCHRP Report 609: ''Recommended Construction Specifications Process Control Manual for Repair and Retrofit of Concrete Structures Using Bonded FRP Composites''
:: '''*''' AASHTO Guide Spec for Design of Bonded FRP Systems for Repair and Strengthening of Concrete Bridge Elements, March 2023, 2nd Ed.


&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ≤ Maximum nominal driving resistance.


'''<sup>7</sup>''' Axial Compressive Resistance values shown above shall be reduced when downdrag is considered


'''<sup>8</sup>''' Maximum factored axial load per pile ≤ Structural factored axial compressive resistance


'''<sup>9</sup>''' Net area of steel pipe, A<sub>st</sub>, assumes a 12.5% fabrication reduction (ASTM A252) and 1/16" (LRFD 5.13.4.5.2) reduction in pipe nominal wall thickness for corrosion.


===I5. Fiber Reinforced Polymer (FRP) Wrap – Intermediate Bent Column Strengthening for Seismic Details for Widening. Report following notes on Intermediate bent plan details.===
'''<sup>10</sup>''' Use for lateral load analysis. Resistance value includes filled pipe based on net area of steel pipe, A<sub>st</sub> (12.5% fab. reduction and 1/16” corr. reduction in nominal pipe wall thickness).


'''(I5.1)'''  
'''<sup>11</sup>''' 5/8” wall thickness is less commonly available than the smaller wall thicknesses of pipe pile.  
:Factored axial resistance of new columns = _____ kip and factored axial resistance of existing columns = _____ kip. The factored axial resistance of the existing column with FRP wrap shall not be less than the factored axial resistance of the new columns.


'''(I5.2)''' 
'''Notes:
:See special provisions.


----
Drivability analysis shall be performed for all CIP piles (unfilled pipe) using Delmag D19-42. Do not show minimum hammer energy on plans.


Check drivability for all CIP Pile in accordance with [[#751.36.5.11 Check Pile Drivability|EPG 751.36.5.11]].


='''REVISION REQUEST 4036'''=
Require dynamic pile testing for field verification for all CIP piles on the plans.


ϕ<sub>dyn</sub> = 0.65 = Dynamic Testing resistance factor to be used to estimate nominal pile resistance during pile installation. This value may be increased if static load testing is specified per LRFD Table 10.5.5.2.3-1.


For additional design requirements, see [[#751.36.5.1 Design Procedure Outline|EPG 751.36.5.1]].
|}
</center>


==106.3.2.93.1 Means of Evaluating Aggregate Alkali Carbonate Reactivity==
===751.36.5.8 Additional Provisions for Pile Cap Footings===
'''Pile Group Layout:'''


'''1. Chemical Analysis'''
P<sub>u</sub> = Total Factored Vertical Load.


The chemical analysis of aggregate reactivity is an objective, quantifiable and repeatable test.  MoDOT will perform the chemical analysis per the process identified in ASTM C 25 for determining the aggregate composition.  The analysis determines the calcium oxide (CaO), magnesium oxide (MgO), and aluminum oxide (Al<sub>2</sub>O<sub>3</sub>) content of the aggregate.  The chemical compositions are then plotted on a chart with the CaO/MgO ratio on the y-axis and Al<sub>2</sub>O<sub>3</sub> percentage on the x-axis per Fig. 2 in AASHTO R 80.  Aggregates are considered potentially reactive if the Al<sub>2</sub>O<sub>3</sub> content is greater than or equal to 1.0% and the CaO/MgO ratio is either greater than or equal to 3.0 or less than or equal to 10.0 (see chart below). See flow charts in 106.3.2.93.2 for approval hierarchy. CaO, MgO and Al2O3 shall be analyzed by instrumental analysis only.
Preliminary Number of Piles Required = <math>\, \frac{Total\ Factored\ Vertical\ Load}{PFDC}</math>


[[File:106.3.2.93.1_Potentially_Expansive_Aggregate_Limits-01.png|700px]]
Layout a pile group that will satisfy the preliminary number of piles required. Calculate the maximum and minimum factored load applied to the outside corner piles assuming the pile cap/footing is perfectly rigid. The general equation is as follows:


<nowiki>*</nowiki> MoDOT’s upper and lower limits of potentially reactive (shaded area) aggregates.
Max. Load = &nbsp; <math>\, \frac {P_u}{Total\ No.\ of\ Piles} + \frac {M_{ux} Y_i}{\Sigma Y_i^2} + \frac {M_{uy} X_i}{\Sigma X_i^2}</math>


'''2.  Petrographic Examination'''
Min. Load = &nbsp; <math>\, \frac {P_u}{Total\ No.\ of\ Piles} - \frac {M_{ux} Y_i}{\Sigma Y_i^2} - \frac {M_{uy} X_i}{\Sigma X_i^2}</math>


A petrographic examination is another means of determining alkali carbonate reactivity.  The sample aggregate for petrographic analysis will be obtained at the same time as the source sample.  MoDOT personnel shall be present at the time of sample.  The petrographic sample shall be placed in an approved tamper-evident container (provided by the quarry) for shipment to petrographer.  Per ASTM C 295, a petrographic examination is to be performed by a petrographer with at least 5 years of experience in petrographic examinations of concrete aggregate including, but not limited to, identification of minerals in aggregate, classification of rock types, and categorizing physical and chemical properties of rocks and minerals.  The petrographer will have completed college level course work in mineralogy, petrography, or optical mineralogy.  MoDOT does not accept on-the-job training by a non-degreed petrographer as qualified to perform petrographical examinations.  MoDOT may request petrographer’s qualifications in addition to the petrographic report.  The procedures in C 295 shall be used to perform the petrographic examination. The petrographic examination report to MoDOT shall include at a minimum:
The maximum factored load per pile must be less than or equal to PFDC for the pile type and size chosen.  If not, the pile size must be increased or additional piles must be added to the pile group.  Reanalyze until the pile type, size and layout are satisfactory.


:* Quarry name and ledge name; all ledges if used in combination
:* MoDOT District quarry resides
:* Date sample was obtained; date petrographic analysis was completed
:* Name of petrographer and company/organization affiliated
:* Lithographic descriptions with photographs of the sample(s) examined
:* Microphotographs of aggregate indicating carbonate particles and/or other reactive materials
:* Results of the examination
:* All conclusions related to the examination 


See flow charts in EPG 106.3.2.93.2 for the approval hierarchy.  See EPG 106.3.2.93.3 for petrographic examination submittals.  No direct payment will be made by the Commission for shipping the petrographic analysis sample to petrographer, or for the petrographic analysis performed by the petrographer. 
'''Pile Uplift on End Bearing Piles and Friction Piles:'''
 
'''3.  Concrete Prism/Beam Test'''


ASTM C 1105 is yet another means for determining the potential expansion of alkali carbonate reactivity in concrete aggregate.  MoDOT will perform this test per C 1105 at its Central Laboratory.  Concrete specimen expansion will be measured at 3, 6, 9, and 12 months.  The test specimens will be considered alkali carbonate reactive (expansive) if the specimens expand greater than 0.015% at 3 months, 0.025% at 6 months, or 0.030% at 12 months.  See flow chart in EPG 106.3.2.93.2 for the approval hierarchy.
:'''Service - I Limit State:'''


----
::Minimum factored load per pile shall be ≥ 0.
::Tension on a pile is not allowed for conventional bridges.


:'''Strength and Extreme Event Limit States:'''


='''REVISION REQUEST 4038'''=
::Uplift on a pile is not preferred for conventional bridges.
::Maximum Pile Uplift load = │Minimum factored load per pile│ - │Factored pile uplift resistance│ ≥ 0<sup>'''1'''</sup>


==1018.5 Laboratory Procedures for Sec 1018==
:::'''Note:''' Compute maximum pile uplift load if value of minimum factored load is negative.
===1018.5.1 Sample Preparation===
Prior to testing, the sample should be thoroughly mixed, passed through a No.20 [850 mm] sieve, and brought to room temperature. All foreign matter and lumps that do not pulverize easily in the fingers must be discarded.


===1018.5.2 Procedure===
::::<sup>'''1'''</sup> The minimum factored load (maximum tensile load) per pile should preferably not result in uplift for the Strength and Extreme Event Limit States. Pile uplift for the Strength and Extreme Event limit states may be permitted by SPM or SLE based on infrequent uplift load cases and small magnitudes of uplift. This decision is based on the presumed difficulty of a pile cap footing to rotate, specifically for it to be able to rotate on piles driven to rock. When pile uplift is allowed, the necessity of top pile cap reinforcement shall be investigated and the standard  anchorage detail for HP pile per [[#751.36.4.1 Structural Steel HP Pile - Details|EPG 751.36.4.1 Structural Steel HP Pile - Details]] shall be used.
Chemical analysis is to be conducted according to ASTM C114 and MoDOT Test Methods T46 and T91. Original test data and calculations are to be recorded in Laboratory workbooks. Test results are to be recorded through AWP and retained on file in the Laboratory.


Physical tests on the following are to be conducted in accordance with ASTM C311.
:(a) Fineness, 325 (45 mm) sieve analysis  ASTM C430
:(b) Pozzolanic Activity Index (7 day)  ASTM C311
:(c) Water requirement  ASTM C311
:(d) Soundness, autoclave ASTM C311
:(e) Specific Gravity ASTM C311
Original test data and calculations are to be recorded in Laboratory workbooks. Test results are to be recorded through AWP and retained on file in the Laboratory.


===1018.5.3 Source Acceptance===
'''Resistance of Pile Groups in Compression'''&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'''LRFD 10.7.3.9'''
Samples are to be taken by the manufacturer in accordance with ASTM C311 from the conveyor, after exiting the precipitator collector and prior to entry into the designated storage silo, or where designated by the engineer.


Ash, that is manually sampled and tested every 400 tons, is to be held until the required tests have been run and the results are properly certified and are available for pick up by MoDOT personnel prior to shipment.
If the cap is not in firm contact with the ground and if the soil at the surface is soft, the individual nominal resistance of each pile (751.36.5.5) shall be multiplied by an efficiency factor, <math>\eta</math>, based on pile spacing.


Ash, that is continually sampled and tested at a frequency and duration acceptable to the engineer, can be continuously shipped direct from a generating station silo, provided the following minimum criteria are met:
===751.36.5.9 Estimate Pile Length and Check Pile Capacity===
:a. The storage silo has a minimum capacity of two days production or 1000 tons, whichever is the largest.
:b. The storage silo is full, and certified test results on the entire contents are available prior to the first shipment.
:c. The ash quantity in the silo is never less than 400 tons.
:d. A continual inventory of the quantity of ash in silos is maintained within one shift of being correct.
:e. The engineer has free access to station facilities and records necessary to conduct inspection and sampling.
:f. All ash conveyance lines to the designated silo or silos will be sampled after precipitator collector and prior to entry into the designated silo(s) where designated by the engineer.
:g. The generating station personnel handle and expedite all documents required to ship by MoDOT Certification.


===1018.5.4 Plant Inspection===
====751.36.5.9.1 Estimated Pile Length====
Qualified fly ash manufacturers and terminals shipping material by certification to Department projects shall be inspected on a regular basis by a representative of the Laboratory. This inspection shall include a review of plant facilities for producing a quality product; plant testing procedures; frequency of tests; plant records of daily test results and shipping information; company certification procedures of silos, bins, and/or shipments; and a discussion of items of mutual interest between the plant and the Department. The Laboratory representative shall coordinate test results and test procedures between the Laboratory and the respective plant laboratory, and investigate associated problems.


All silo or bin certifications and results of complete physical and chemical tests received in the Laboratory are to be checked for specification compliance and to determine if the required certifications have been furnished.
'''Friction Piles:'''


===1018.5.5 Sample Record===
Estimate the pile length required to achieve the minimum nominal axial compressive resistance, MNACR, or required driving resistance, R<sub>ndr</sub>, for establishment of contract pile quantities. Perform a static analysis using one of the methods given in EPG [[751.36_Driven_Piles#751.36.5.3_Geotechnical_Resistance_Factor_(ϕstat)_and_Driving_Resistance_Factor_(ϕdyn)|751.36.5.3 Geotechnical Resistance Factor (ϕ<sub>stat</sub>) and Driving Resistance Factor (ϕ<sub>dyn</sub>)]] to determine the nominal resistance profile of the soil. For each soil layer the appropriate resistance factor, ϕ<sub>stat</sub>, shall be applied to account for the reliability of the static analysis method to create a factored resistance profile. The penetration depth would then occur at the location where the factored resistance profile intercepts the factored load. The relationship between the static axial compressive resistance and required driving resistance for a uniform soil profile with a constant static resistance factor is given as follows:
The sample record shall be completed in AASHTOWARE Project (AWP) in accordance with [[:Category:101 Standard Forms #Sample Record, General|AWP MA Sample Record, General]], and shall indicate acceptance, qualified acceptance, or rejection. Appropriate remarks, as described in [[106.20 Reporting|EPG 106.20 Reporting]], are to be included in the remarks to clarify conditions of acceptance or rejections. Test results shall be reported on the appropriate templates under the Tests tab.
:{| style="margin: 1em auto 1em auto"
|-
|ϕ<sub>dyn</sub> x R<sub>ndr</sub> = ϕ<sub>stat</sub> x R<sub>nstat</sub> ≥ Factored Load||width="450"| ||LRFD C10.7.3.3-1
|}


Where:
:ϕ<sub>dyn</sub> = see [[#751.36.5.3 Geotechnical Resistance|EPG.751.36.5.3]]
:R<sub>ndr</sub> = Required nominal driving resistance = MNACR
:ϕ<sub>stat</sub> = Static analysis resistance factor per [[751.36_Driven_Piles#751.36.5.3_Geotechnical_Resistance_Factor_(ϕstat)_and_Driving_Resistance_Factor_(ϕdyn)|EPG 751.36.5.3]] or as provided by the Geotechnical Engineer. Factors for side friction and end bearing may be different.
:R<sub>nstat</sub> = Required nominal static resistance


Use soil profiles from borings and mimic soil characteristics as closely as possible in computations or software to calculate the geotechnical resistance and for estimating the length of pile. For more detailed guidance see [https://www.modot.org/media/54989 SEG 25-001 New Policy for Friction Pile].


----
It is not advisable to design pile deeper than available borings or to reach capacity within the bottom 3 to 5 feet of borings. If a longer pile depth is needed to meet design requirements then request Geotechnical Section to provide deeper borings or increase the number of piles which will reduce load per pile as well as the required pile length.


='''REVISION REQUEST 4041'''=
For friction pile the top five feet of soil friction resistance may be neglected with SPM or SLE approval for possible disturbance from MSE wall excavation prior to driving pile.


'''End Bearing Piles:'''


===751.31.2.4 Column Analysis===
The estimated pile length is the distance along the pile from the cut-off elevation to the estimated tip elevation considering any penetration into rock. The estimated tip elevation shall not be shown on plans for end bearing piles.  


Refer to this article to check slenderness effects in column and the moment magnifier method of column design. See Structural Project Manager for use of P Delta Analysis.
The geotechnical material above the estimated end bearing tip elevation shall be reviewed for the presence of glacial till or similar layers. If these layers are present, then a static analysis shall be performed to verify if the required pile resistance is reached at a higher elevation due to pile friction capacity.


====751.36.5.9.2 Check Pile Geotechnical Capacity (Axial Loads Only)====


'''Transverse Reinforcement'''
Use the same methodology outlined in [[#751.36.5.9.1 Estimated Pile Length|EPG 751.36.5.9.1 Estimated Pile Length]].


''Seismic Design Category (SDC) A''
====751.36.5.9.3 Check Pile Structural Capacity (Combined Axial and Bending)====
:Columns shall be analyzed as “Tied Columns”.  Unless excessive reinforcement is required, in which case spirals shall be used.


'''Bi-Axial Bending'''
Structural design checks which include lateral loading and bending shall be accomplished using the appropriate structural resistance factors.


Use the resultant of longitudinal and transverse moments.
===751.36.5.10 Pile Nominal Axial Compressive Resistance ===
The minimum nominal axial compressive resistance, MNACR, or required driving resistance, R<sub>ndr</sub>, must be calculated and shown on the final plans. The factored axial compressive resistance will be used to verify the pile group layout and loading. The minimum nominal axial compressive resistance will be used in construction field verification methods to obtain the required nominal driving resistance.  


'''Slenderness effects in Columns'''
: Minimum Nominal Axial Compressive Resistance, MNACR = Required Nominal Driving Resistance, R<sub>ndr</sub> 
: = Maximum factored axial loads/ϕ<sub>dyn</sub>
:ϕ<sub>dyn</sub> = Resistance factor of the dynamic method used to estimate nominal pile resistance during pile installation. LRFD 10.5.5.2.3.1


The slenderness effects shall be considered when:
The value of R<sub>ndr</sub> shown on the plans shall be the greater of the value required at the '''Strength limit state and Extreme Event limit state'''.  This value shall not be greater than the structural nominal axial compressive resistance of the steel HP pile nor shall it exceed the maximum nominal driving resistance of the steel shell for CIP piles.  See [[#751.36.5.5 Preliminary Structural Nominal Axial Design Capacity (PNDC) of an individual pile |EPG 751.36.5.5]]. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; LRFD 10.7.7


<math>\, \ l_u \ge \frac {22r}{K}</math>
For friction piles predominantly embedded and tipped in cohesionless soils the minimum nominal axial compressive resistance shall be limited to the values shown in the following table. Approval from the SPM, SLE or owner's representative is required before exceeding the limits provided in this table.


Where:  
{| border="1" style="text-align:center;" cellpadding="5" align="center" cellspacing="0"
   
|+ '''Maximum Axial Loads for Friction Pile in Cohesionless Soils'''
<math>\, \ l_u</math> = unsupported length of column
! rowspan="3" | Pile Type !! rowspan="3" | Minimum Nominal<br/>Axial Compressive<br/>Resistance (R<sub>ndr</sub>)<sup>'''1'''</sup><br/>(kips)<br/> !! colspan="3" | Maximum Factored Axial Load (kips)
 
|-
<math>\, \ r</math> = radius of gyration of column cross section
! Dynamic Testing !! Wave Equation<br/>Analysis !! FHWA-modified<br/>Gates Dynamic<br/>Pile Formula
 
|-
<math>\, \ K</math> = effective length factor
! ϕ<sub>dyn</sub>= 0.65 !! ϕ<sub>dyn</sub> = 0.50 !! ϕ<sub>dyn</sub> = 0.40
 
|-
Effects should be investigated by using either the rigorous P-∆ analysis or the Moment Magnifier Method with consideration of bracing and non-bracing effects.  Use of the moment magnifier method is limited to members with Kl<sub>u</sub>/r ≤ 100, or the diameter of a round column must be ≥ Kl<sub>u</sub>/25. A maximum value of 2.5 for moment magnifier is desirable for efficiency of design.  Increase column diameter to reduce the magnifier, if necessary.
| CIP 14” || 210 || 136 || 105 || 84
 
When a compression member is subjected to bending in both principal directions, the effects of slenderness should be considered in each direction independently.  Instead of calculating two moment magnifiers, <math>\, \delta_b</math> and <math>\, \delta_s</math>, and performing two analyses for M<sub>2b</sub> and M<sub>2s</sub> as described in LRFD 4.5.3.2.2b, the following conservative, simplified moment magnification method in which only a moment magnifier due to sidesway, δ<sub>s</sub>, analysis is required:
<center>
[[Image:751.31 Open Concrete Int Bents and Piers- Typical Intermediate Bent.gif]]
</center>
 
<center>'''Typical Intermediate Bent'''</center>
 
 
''General Procedure for Bending in a Principal Direction''
 
::M<sub>c</sub> = δ<sub>s</sub>M<sub>2</sub>
 
::Where:
::M<sub>c</sub> = Magnified column moment about the axis under investigation.
 
::M<sub>2</sub> = value of larger column moment about the axis under investigation due to LRFD Load Combinations.
 
::δ<sub>s</sub> = moment magnification factor for sidesway about the axis under investigation
 
::<math>\, =\cfrac{C_m}{1- \cfrac{\sum P_u }{\phi_k \sum P_e }} \ge 1.0; \ C_m = 1.0 </math>
 
Where:
{|style="text-align:left"
|-
|-
|<math>\, \sum P_u</math> ||=||summation of individual column factored axial loads for a specific Load Combination (kip)
| CIP 16” || 240 || 156 || 120 || 96
|-
|-
|<math>\, \phi_K</math> ||=||stiffness reduction factor for concrete = 0.75
| CIP 20” || 300 || 195 || 150 || 120
|-
|-
|<math>\, \sum P_e</math>|| =||summation of individual column Euler buckling loads
| CIP 24” || 340 || 221 || 170 || 136
|-
|-
| colspan="5" align="left" | <sup>'''1'''</sup> The minimum nominal axial compressive resistance values are correlated to match the maximum design tonnage values used in past ASD practice.  A factor of safety of 3.5 is used to determine the equivalent R<sub>ndr</sub>.
|}
|}


<math>\, =\sum {\frac{\pi^2 \ EI}{\left( \ Kl_u \right)^2}}</math>
===751.36.5.11 Check Pile Drivability===
Drivability of the pile through the soil profile shall be investigated using the GRLWEAP wave equation analysis program. The static axial compressive resistance profile used in the wave equation analysis shall be determined using one of the approved static methods given in [[751.36_Driven_Piles#751.36.5.3_Geotechnical_Resistance_Factor_(ϕstat)_and_Driving_Resistance_Factor_(ϕdyn)|EPG 751.36.5.3]].
Drivability analysis shall be performed by the designer for all pile types (bearing pile and friction pile) using the Delmag D19-42 hammer with manufacturer recommendations. The drivability analysis shall confirm that the pile can be driven to the minimum tip elevation, rock elevation or reach the minimum nominal axial compressive resistance prior to refusal and without overstressing the pile. If the drivability analysis shows overstress or refusal prior to reaching the desired depth a lighter or heavier hammer from the table below may be used to confirm constructability. The drivability analysis is not intended to confirm that a pile can be driven through rock (shales, sandstones, etc…) where the likelihood of pile damage is increased and PDA is recommended to reduce loads and monitor pile stresses in the field. The drivability analyses performed by the designer does not waive the responsibility of the contractor in selecting the appropriate pile driving system per Sec 702.3.5 (also discussed below).


Where:
Use soil profiles from borings and mimic soil characteristics as closely as possible for computations or in software to perform drivability analysis of any kind of pile.


<math>\, \ K</math> = effective length factor = 1.2 min. (see the following figure showing boundary conditions for columns)
'''Structural steel HP Pile:'''


<math>\, \ l_u</math> = unsupported length of column (in.)
Drivability analysis shall be performed for the box shape of the pile (i.e., not the perimeter).


<math>\, \ EI = \cfrac{{E_cI_g}{/2.5}}{1+\beta_d}</math>
Drivability shall be performed considering existing condition without considering any excavation/ disturbance (i.e., possible disturbance to top 5 feet of soil from MSE wall excavation prior to driving pile), liquefaction or future scour loss.


Where:
'''Hammer types:'''


<math>\, \ E_c</math>= concrete modulus of elasticity as defined in [[751.31 Open Concrete Intermediate Bents#751.31.1.1 Material Properties|EPG 751.31.1.1]] (ksi)
{| border="1" style="text-align:center;" cellpadding="5" align="center"  cellspacing="0"
 
|+ '''Pile Driving Hammer Information For GRLWEAP'''
<math>\, \ I_g</math>= moment of inertia of gross concrete section about the axis under investigation <math>\, (in^4)</math>
! colspan="3" | Hammer used in the field per survey response (2017)
 
|-
<math>\, \beta_d</math>= ratio of maximum factored permanent load moments to maximum factored total load moment: always positive
! GRLWEAP ID !! Hammer name !! No. of Responses
 
|-
 
| 41 || Delmag D19-42<sup>1</sup> || 13
''Column Moment Parallel to Bent In-Plane Direction''
|-
 
| 40 || Delmag D19-32 || 6
<math>M_{cy}= \delta_{sy}M_{2y}</math>
 
<math>l_{uy}</math>= top of footing to top of beam cap
 
 
''Column Moment Normal to Bent In-Plane Direction''
 
<math>M_{cz}= \delta_{sz}M_{2z}</math>
 
<math>l_{uz}</math> = top of footing to bottom of beam cap or tie beam and/or top of tie beam to bottom of beam cap
 
{| style="margin: auto;"
|-
|-
| Out-of-plane bending<br>Non-integral Bent<sup>1</sup> || [[Image:751.31 Open Concrete Int Bents and Piers- Boundary Conditions for columns-Top Image.gif]] || Out-of-plane bending<br>Integral Bent
| 38 || Delmag D12-42 || 4
|-
|-
| In-plane bending || [[Image:751.31 Open Concrete Int Bents and Piers- Boundary Conditions for columns-Bottom Image.gif]] ||  
| 139 || ICE 32S || 4
|-
|-
| colspan="3" | '''Boundary Conditions for Columns'''
| 15 || Delmag D30-32 || 2
|-
|-
| colspan="3" | <sup>1</sup>A refined procedure may be used to determine a reduced effective length factor (less than 2.1) for<br>intermediate bents where the beam cap is doweled into a concrete superstructure diaphragm. The<br>procedure is outlined at the end of this section.
| || Delmag D25-32 || 2
|-
|-
|}
| 127 || ICE 30S || 1
 
For telescoping columns, the equivalent moment of inertia, <i>I</i>, and equivalent effective length factor, <i>K</i>, can be estimated as follows:
 
{| style="margin: auto; text-align: center"
|-
|-
| [[Image:751.31 Open Concrete Int Bents and Piers- Telescoping Columns.gif|center]]
| 150 || MKT DE-30B || 1
|-  
| '''Telescoping Columns'''
|-
|-
| colspan="3" | <sup>'''1</sup>''' Delmag series of pile hammers is the most popular, with the D19-42 being the most widely used.
|}
|}


<math>\, \ I = \frac {\sum \left(l_n I_n \right)}{L}</math>
The contractor is responsible for determining the driving system required to successfully drive the pile to the minimum tip elevation and to reach the minimum nominal axial compressive resistance specified on the plans. The contractor is required to perform a drivability analysis to select an appropriate hammer size to ensure the pile can be driven without overstressing the pile and to prevent refusal of the pile prior to reaching the minimum tip elevation. The contractor shall plan pile driving activities and submit hammer energy requirements to the engineer for approval before driving. There is an exception to the contractor’s responsibility for the drivability analysis when WEAP is specified as the driving criteria for friction pile. When WEAP is specified for friction pile an inspector’s chart will be provided for the contractor in the electronic deliverables. For more detailed guidance see [https://www.modot.org/media/54989 SEG 25-001 New Policy for Friction Pile].


Where:
Practical refusal is defined at 20 blows/inch or 240 blows per foot. 


<math>\, l_n</math>= length of column segment <math>\, n</math>
Driving should be terminated immediately once 30 blows/inch is encountered.


<math>\, I_n</math>= moment of inertia of column segment <math>\, n</math>
:{| style="margin: 1em auto 1em auto"
|-
|'''Nominal Driving Stress'''||width="840"| ||'''LRFD 10.7.8'''
|}
:Nominal driving stress ≤ 0.9*ϕ<sub>da</sub>*F<sub>y</sub>
::For structural steel HP pile, Maximum nominal driving stress = 45 ksi
::For CIP pile, Maximum nominal driving resistance, see [[#751.36.5.7.2.1 Design Values for Individual HP Pile|EPG 751.36.5.7.1.2]] or [[#751.36.5.7.2.2 Design Values for Individual Cast-In-Place (CIP) Pile|EPG 751.36.5.7.2.2]] (unfilled pipe for axial analysis).
If analysis indicates the piles do not have sufficient structural or geotechnical strength or drivability issues exist, then consider increasing the number of piles.


<math>\, L</math>= total length of telescoping column
===751.36.5.12 Information to be Included on the Plans===
 
 
See [https://epg.modot.org/index.php?title=751.50_Standard_Detailing_Notes#A1._Design_Specifications.2C_Loadings_.26_Unit_Stresses EPG 751.50 A1 Design Specifications, Loadings & Unit Stresses] for appropriate design stresses to be included in the general notes.
'''Equivalent Effective Length Factor'''


<math>\, \ K =\sqrt \frac{\pi^2EI}{P_cL^2}</math>
See [https://epg.modot.org/index.php?title=751.50_Standard_Detailing_Notes#E2._Foundation_Data_Table EPG 751.50 E2 Foundation Data Table] for appropriate data to be included in the foundation data table for HP pile and CIP pile and any additional notes required below the table. See [https://www.modot.org/pile-pile  Bridge Standard Drawings “Pile”] for CIP data table.
 
Where:


<math>\, E</math> = modulus of elasticity of column


<math>\, I</math> = equivalent moment of inertia of column
<br><br>
<hr style="border:none; height:2px; background-color:red;" />
<br><br>


<math>\,L</math> = total length of telescoping column


<math>\, P_c</math> =elastic buckling load solved from the equations given by the following boundary conditions:
=== E2. Foundation Data Table ===


Warning: The following equations were developed assuming equal column segment lengths. When the segment lengths become disproportionate other methods should be used to verify P<sub>c</sub>.
The following table is to be placed on the design plans and filled out as indicated.


'''(E2.1) <font color="purple">[MS Cell] (E2.1)</font color="purple"> (Example: Use the underlined parts in the bent headings for bridges having detached wing walls at end bents only.) '''


<center>
<center>
''Fixed-Fixed Condition''
{|border="1" style="text-align:center;" cellpadding="5" cellspacing="0"
 
|-
[[Image:751.31 Open Concrete Int Bents and Piers- Columns Fixed-Fixed Condition.gif]]
!colspan="8" style="background:#BEBEBE"| Foundation Data<sup>1</sup>
 
|-
 
!rowspan="2" style="background:#BEBEBE"|Type!!rowspan="2" style="background:#BEBEBE" colspan="2"|Design Data!!colspan="5" style="background:#BEBEBE"| Bent Number
<math>\, \left(a_1 + a_2 \right) \bigg[ \left(d_1 + d_2 \right) - P_c \Big( \frac{1}{l_1} + \frac{1}{l_2} \Big) \bigg]- \left(c_1 - c_2 \right)^2 = 0</math>
 
{|
|-
|-
|<math>\, a_1</math>||<math>\, = \frac{4EI_1}{l_1}</math>||width="100"|&nbsp;||<math>\, a_2</math>||<math>\, =\frac{4EI_2}{l_2}</math>
!style="background:#BEBEBE"|1 <u>(Detached<br/>Wing Walls<br/>Only)</u> !!style="background:#BEBEBE"|1 <u>(Except<br/>Detached<br/>Wing Walls)</u> !!style="background:#BEBEBE"|2 !!style="background:#BEBEBE"| 3 !!style="background:#BEBEBE"|4
|-
|-
|<math>\, c_1</math>||<math>\, = \frac{6EI_1}{{l_1}^2}</math>||&nbsp;||<math>\, c_2</math>||<math>\, =\frac{6EI_2}{{l_2}^2}</math>
|rowspan="11"|'''Load<br/>Bearing<br/>Pile'''|| colspan="2" align="left" width="300"|CECIP/OECIP/HP Pile Type and Size||CECIP 14"||CECIP 14"||CECIP 16"|| OECIP 24"||HP 12x53
|-
|-
|<math>\, d_1</math>||<math>\, = \frac{12EI_1}{{l_1}^3}</math>||&nbsp;||<math>\, d_2</math>||<math>\, = \frac{12EI_2}{{l_2}^3}</math>
|colspan="2" align="left" width="300"|Number [[image:751.50 ea.jpg|34px|right]]||6||8||15||12||6
|-
|-
|}
|colspan="2" align="left" width="300"|Approximate Length Per Each [[image:751.50 ft.jpg|20px|right]]||50||50||60||40||53
 
 
''Hinged-Fixed Condition''
 
[[Image:751.31 Open Concrete Int Bents and Piers- Columns Hinged-Fixed Condition.gif]]
</center>
 
{|align="center"
|-
|-
|<math>\, \left(a_2 \right) \left(a_1 + a_2 \right) \bigg[ \left(d_1 + d_2 \right) - P_c \Big( \frac{1}{l_1} + \frac{1}{l_2} \Big) \bigg]- \left(2b_2c_2 \right) \left(c_2 - c_1 \right) </math>
|colspan="2" align="left" width="300"|Pile Point Reinforcement[[image:751.50 ea.jpg|34px|right]]||All||All|| - ||All||All
|-
|-
|<math>- \left(b_2 \right)^2 \bigg[ \left(d_1 + d_2 \right) - P_c \Big( \frac{1}{l_1} + \frac{1}{l_2} \Big) \bigg]- \left(a_2 \right) \left(c_2 - c_1 \right)^2</math>
|colspan="2" align="left" width="300"|Min. Galvanized Penetration (Elev.) [[image:751.50 ft.jpg|20px|right]]||303||295<sup>'''4'''</sup>||273||Full Length||300
|-
|-
|<math>- \left(c_2 \right)^2 \left(a_2 + a_1 \right) = 0 </math>
|colspan="2" align="left" width="300"|Est. Max. Scour Depth 100<sup>'''2'''</sup> (Elev.) [[image:751.50 ft.jpg|20px|right]]|| - || - ||285 || - || -
|}
 
Where:
{|
|-
|-
|<math>\, b_1</math>||<math>\, = \frac{2EI_1}{l_1}</math>||width="100"|&nbsp;||<math>\, b_2</math>||<math>\, =\frac{2EI_2}{l_2}</math>
|colspan="2" align="left" width="300"|Minimum Tip Penetration (Elev.) [[image:751.50 ft.jpg|20px|right]]||285||303||270|| - || -
|-
|-
|}
|colspan="2" align="left" width="300"|Criteria for Min. Tip Penetration ||Min. Embed.||Min. Embed.|| Scour || - || -
 
<math>\, a_1, a_2, c_1, c_2, d_1,</math> and <math>\, d_2</math> are defined in the previous equations.
 
 
<center>
''Fixed-Fixed with Lateral Movement Condition''
 
[[Image:751.31 Open Concrete Int Bents and Piers- Fixed-Fixed Lateral Movement Condition.gif]]
</center>
 
{|align="center"
|-
|-
|<math>\, \bigg[(d_1 + d_2) - \frac{(c_2 - c_1)^2}{a_1 + a_2} - P_c \Bigg( \frac{1}{l_1} + \frac{1}{l_2} \Bigg) \bigg] \bigg[d_2 - \frac{{c_2}^2}{a_1 + a_2} - P_c \Bigg(\frac {1}{l_2} \Bigg) \Bigg]</math>
|colspan="2" align="left" width="300"|Pile Driving Verification Method || DT ||DT ||DT||DT||DF
|-
|-
|<math>- \Bigg[(-d_2) + \frac{c_2 (c_2 - c_1)}{a_1 + a_2} + P_c \Bigg(\frac{1}{l_2} \Bigg) \Bigg]^2 = 0</math>
|colspan="2" align="left" width="300"|Resistance Factor||0.65|| 0.65|| 0.65|| 0.65|| 0.4
|}
 
Where:
 
<math>\, a_1, a_2, b_1, b_2, c_1, c_2, d_1,</math> and <math>\, d_2</math> are defined in the previous equations.
 
 
<center>
''Fixed-Free with Lateral Movement Condition''
 
[[Image:751.31 Open Concrete Int Bents and Piers- Fixed-Free Lateral Movement Condition.gif]]
</center>
 
{|align="center"
|-
|-
|<math>\, \Bigg[ (d_1 + d_2) - P_c \Bigg( \frac{1}{l_1} + \frac{1}{l_2} \Bigg) - \frac{A_1}{\beta} \Bigg] \Bigg[ d_2 - \frac{P_c}{l_2} - \frac{A_3}{\beta} \Bigg]</math>
|colspan="2" align="left" width="300"|<u>Design Bearing</u><sup>'''3'''</sup> <u>Minimum Nominal Axial</u><br/><u>Compressive Resistance</u> [[image:751.50 kip.jpg|27px|right]]||175||200||300||600||250
|-
|-
|<math>\, - \Bigg[(-d_2) + \frac{P_c}{l_2} - \frac{A_2}{\beta} \Bigg]^2 = 0</math>
|rowspan="2"|'''Spread<br/>Footing||colspan="2" align="left"|Foundation Material || - || - ||Weak Rock||Rock|| -
|}
 
Where:
{|
|<math>\, \beta</math>|| <math>\, = (a_2)(a_1 + a_2) - ( b_2)^2</math>
|-
|-
|<math>\, A_1</math>|| <math>\, = (c_1 - c_2)[a_2(c_1 - c_2) + (b_2c_2)] + (c_2)[b_2(c_1 - c_2) + (c_2)(a_1 + a_2)]</math>
|colspan="2" align="left"|<u>Design Bearing</u> <u>Minimum Nominal</u><br/><u>Bearing Resistance</u> [[image:751.50 ksf.jpg|30px|right]]|| - || - ||10.2||22.6|| -
|-
|-
|<math>\, A_2</math>|| <math>\, = (c_1 - c_2)[(a_2c_2) - (b_2c_2)] + (c_2)[(b_2c_2) - (c_2)(a_1 + a_2)]</math>
|rowspan="8"|'''Rock<br/>Socket'''||colspan="2" align="left"|Number [[image:751.50 ea.jpg|34px|right]]|| - || - || 2 ||3|| -
|-
|-
|<math>\, A_3</math>|| <math>\, = (c_2)[(a_2c_2) - (2b_2c_2) + (c_2)(a_1 + a_2)]</math>
|rowspan="3" width="35"|[[image:751.50 Layer 1.jpg|center|24px]]||align="left" width="265"|Foundation Material|| - || - || Rock||Rock|| -
|-
|-
|colspan="2"|&nbsp;
| align="left"|Elevation Range [[image:751.50 ft.jpg|20px|right]]|| - || - ||410-403||410-398|| -
|-
|-
|colspan="2"|<math>\, a_1, a_2, b_1, b_2, c_1, c_2, d_1,</math> and <math>\, d_2</math> are defined in the previous equations.
| align="left"|<u>Design Side Friction</u><br/><u>Minimum Nominal Axial</u><br/><u>Compressive Resistance</u><br/><u>(Side Resistance)</u> [[image:751.50 ksf.jpg|30px|right]]|| - || - ||20.0||20.0|| -
|}
 
 
'''Refined Effective Length Factor for Out-of-plane Bending'''
 
The following procedure may be used to reduce the effective length factor for column or pile bents where the beam cap is doweled into a concrete superstructure diaphragm. This procedure is applicable for out-of-plane bending only. The less stiff the substructure the larger the benefit expected from this procedure.
 
The equation for rotational stiffness assumes the dowel bars are fully bonded in the superstructure and beam. To utilize this procedure the dowel bars shall be developed l<sub>d</sub> min into diaphragm and beam but shall not extend into slab and shall clear bottom of beam by 3 inches minimum. Dowel bars shall not be hooked to meet development requirements.
 
{| style="margin: auto; text-align: center"
|-
|-
| [[image:751.31.2.4_09-2025.png|200px|center]]
|rowspan="3"|[[image:751.50 Layer 2.jpg|center|21px]]|| align="left" |Foundation Material|| - || - ||Weak Rock|| - || -
|-
|-
| SECTION THRU KEY
| align="left"|Elevation Range [[image:751.50 ft.jpg|20px|right]]|| - || - ||403-385|| - || -
|-
|-
|}
| align="left"|<u>Design Side Friction</u><br/><u>Minimum Nominal Axial</u><br/><u>Compressive Resistance</u><br/><u>(Side Resistance)</u> [[image:751.50 ksf.jpg|30px|right]]|| - || - ||9.0|| - || -
The following procedure is developed for the most common substructure type (columns on drilled shafts). This procedure is greatly simplified for non-telescoping column bents and pile bents.
 
'''Step 1''' – Determine the rotational stiffness at top of bent per ft length of diaphragm, <math>R_{ki}</math>
 
:: <math>R_{ki}</math> = -12500 + 300A<sub>d</sub> + 600D<sub>W</sub> – 150 x  θ
 
Where:
{|
|-
|-
| style="text-align: right" | <math>R_{ki}</math> || = rotational stiffness at top of bent per ft length of diaphragm (k-ft/rad per ft)
|colspan="2" align="left"|<u>Design End Bearing</u><br/><u>Minimum Nominal Axial</u><br/><u>Compressive Resistance</u><br/><u>(Tip Resistance)</u> [[image:751.50 ksf.jpg|30px|right]]|| - || - ||12||216|| -
|-
|-
| style="text-align: right" | <math>A_{d}</math> || = total area of dowel bars (in2)
|colspan="8" align="left"|'''1'''  Show only required CECIP/OECIP/HP pile data for specific project.
|-
|-
| style="text-align: right" | <math>D_{W}</math> || = diaphragm width between girders and normal to bent (in)
|colspan="8" align="left"|'''2''' Show maximum of total scour depths estimated for multiple return periods in years from Preliminary design which should be given on the Design Layout. Show the controlling return period (e.g. 100, 200, 500). If return periods are different for different bents, add a new line.
|-
|-
| style="text-align: right" | <math>\theta</math> || = skew angle of bent (deg.)
|colspan="8" align="left"|'''3''' For LFD: For bridges in Seismic Performance Categories B, C and D, the design bearing values for load bearing piles given in the table should be the larger of the following two values: <br/> &nbsp; 1. Design bearing value for AASHTO group loads I thru VI. <br/> &nbsp; 2. Design bearing for seismic loads / 2.0
|-
|-
|colspan="8" align="left"|'''4''' It is possible that min. tip penetration (elev.) can be higher than min. galvanized penetration (elev.).
|}
|}


'''Step 2''' – Determine the rotational stiffness at top of column, <math>R_{kb}</math>
{|border="2" style="text-align:center;" cellpadding="5" cellspacing="0"
|-
| align="left"|'''Additional notes:'''<br/> On the plans, report the following definition(s) just below the foundation data table for the specific method(s) used:<br/>
DT = Dynamic Testing<br/>
DF = FHWA-modified Gates Dynamic Pile Formula<br/>
WEAP = Wave Equation Analysis of Piles<br/>
SLT = Static Load Test<br/><br/>On the plans, report the following definition(s) just below the foundation data table for CIP Pile:<br/>CECIP = Closed Ended Cast-In-Place concrete pile<br/>OECIP = Open Ended Cast-In-Place concrete pile<br/><br/>On the plans, report the following equation(s) just below the foundation data table for the specific foundation(s) used:<br/>'''Rock Socket (Drilled Shafts):'''<br/>Minimum Nominal Axial Compressive Resistance (Side Resistance + Tip Resistance) = Maximum Factored Loads/Resistance Factors<br/>'''Spread Footings:'''<br/>Minimum Nominal Bearing Resistance = Maximum Factored Loads/Resistance Factor <br/>'''Load Bearing Pile:'''<br/>Minimum Nominal Axial Compressive Resistance = Maximum Factored Loads/Resistance Factor
|}


To determine the rotational stiffness at top of column, the rotational stiffness at top of bent, <math>R_{ki}</math>, shall be multiplied by the beam cap length and divided by the number of columns. The beam cap length is substituted for the diaphragm length to simplify the calculations and has a marginal affect on the final result.


:: <math>R_{kb}\, =\, \frac{R_{ki}\, (\text{beam cap length})}{(\text{No. Columns})}</math>
</center>


'''Step 3''' – Determine the buckling load assuming no rotational stiffness at top, <math>P_{co}</math>
{|style="padding: 0.3em; margin-left:10px; border:1px solid #a9a9a9; text-align:left; font-size: 95%; background:#f5f5f5" width="700px" align="center"
 
|-
''For a non-telescoping column on footing or pile with in-ground point of fixity:''
|colspan="3" align="left"|<b>Guidance for Using the Foundation Data Table:</b>
 
|-
Note: this step is not required for a non-telescoping column or pile bent but shown here for completeness.
|rowspan="18"| || rowspan="4"|Pile Driving Verification Method ||width="350px"|DF = FHWA-Modified Gates Dynamic Pile Formula
 
|-
:: <math>P_{co}\, =\, \frac{\pi^2EI}{4L^2}\, \, \, \text{... Note: assumes K= 2.0}</math> 
|DT = Dynamic Testing
 
|-
Where:
|WEAP = Wave Equation Analysis of Piles
{|
|-
|SLT = Static Load Test
|-
|colspan="7"  style="background:#BEBEBE"|
|-
|rowspan="7"|Criteria for Minimum Tip Penetration ||Scour
|-
|-
| style="text-align: right" | <math>P_{co}</math> || = initial buckling load assuming no rotational stiffness at top of bent (k)
|Tension or uplift resistance
|-
|-
| style="text-align: right" | <math>E</math> || = modulus of elasticity of column or pile (ksi)
|Lateral stability
|-
|-
| style="text-align: right" | <math>I</math> || = moment of inertia of column or pile for out-of-plane bending (in4)
|Penetration anticipated soft geotechnical layers
|-
|-
| style="text-align: right" | <math>L</math> || = length between point of fixity and top of beam cap (in)
|Minimize post construction settlement
|-
|-
|}
|Minimum embedment into natural ground
 
''For a telescoping column:''
 
As noted above the equations provided for determining the buckling load of telescoping columns are not accurate for diverging segment lengths. The following equation is provided and may be used for the fixed-free with lateral movement condition.
 
:: <math>P_{co}\, =\, \frac{\pi^2EI_2}{4L^2}\, \frac{1}{\frac{l_2}{L} + \frac{l_1 I_2}{LI_1} - \frac{1}{\pi} \left ( \frac{I_2}{I_1} - 1 \right ) sin \frac{\pi l_2}{L}} \, \text{... fixed-free with lateral movement}</math>
 
Where:
{|
|-
|-
| <math>E = \frac{\sum(l_n E_n)}{L}</math>
|Other Reason
|-
|-
| <math>l_1, l_2, I_1, I_2 \text{ and } L \text{ are shown in the figures above.}</math>
|colspan="7" style="background:#BEBEBE"|
|-
|-
|}
|colspan="7"|'''Elevation reporting accuracy: Report to nearest foot for min. tip penetration, pile cleanout penetration, max. galvanized depth and est. max. scour depth. (Any more accuracy is acceptable but not warranted.)'''
 
'''Step 4''' – Determine the equivalent moment of inertia for a non-telescoping column using <math>P_{co}</math>
 
:: <math>I_{eq}\, =\, \frac{P_{co} 4 L^2}{E\pi^2}\, \, \, \text{... Note: assumes K= 2.0}</math>
 
Note: This step is only required for telescoping columns.
 
'''Step 5''' – Determine ideal k
 
A bilinear approximation is used to determine the ideal effective length factor for out-of-plane bending, <math>k</math>.
 
:: <math>
k =
\begin{cases}
2.000 - 0.3135 \left ( \frac{R_{kb}L}{EI_{eq}} \right ) for\, \frac{R_{kb}L}{EI_{eq}} < 2\\
1.428 - 0.0275 \left ( \frac{R_{kb}L}{EI_{eq}} \right ) for\, \frac{R_{kb}L}{EI_{eq}} < 2
\end{cases}
</math>
 
Note: <math>I_{eq} = I</math> for non-telescoping columns or piles
 
[[image:751.31.2.4_10-2025.png|400px|center]]
<center>'''Graphical Approximation of k-factor'''</center>
 
'''Step 6''' – Adjust <math>k</math> for design
 
The effective length factor for out-of-plane bending requires an adjustment for design conditions.
 
:: <math>K\, =\, \frac{2.1k}{2.0}</math>
 
K=2.1k/2.0
 
'''Step 7''' – Determine refined buckling load
 
The buckling load can be calculated using the equivalent non-telescoping column moment of inertia.
 
:: <math>P_{c}\, =\, \frac{\pi^2EI_{eq}}{(KL)^2}</math>
 
 
 
----
 
 
='''REVISION REQUEST 4046'''=
 
==751.21.2 Design==
The design shall be in accordance with the appropriate design guidance found in [[751.22 Prestressed Concrete I Girders#751.22.2 Design|EPG 751.22.2 Design]] except as specified in this article.
 
===751.21.2.1 Distribution Factors===
'''Deck Superstructure Type (LRFD 4.6.2.2.1)'''
 
Spread beams (including voided slab beams) are considered as precast concrete boxes supporting components with a cast-in-place concrete slab deck, typical cross-section (b).
 
Adjacent beams composite with a reinforced concrete slab are considered as precast solid, voided, or cellular concrete boxes with shear keys supporting components with a cast-in-place concrete overlay deck, typical cross-section (f).
 
Adjacent beams with an asphalt wearing surface shall be considered as precast solid, voided, or cellular concrete box with shear keys and with or without transverse post-tensioning supporting components with an integral concrete deck, typical cross-section (g).
 
'''LRFD Exception for Shallow Spread Beams'''
 
The live load distribution factor for moment in interior beams specified for spread beams greater than or equal to 18 inches may be used for the 15- and 17-inch spread beams.
 
===751.21.2.2 Pretensioned Anchorage Zones===
The bursting and spalling resistance in the ends of box beams shall be provided by vertical reinforcement (U1, S4 and S5 bars). The bursting and spalling resistance shall be based on LRFD 5.9.4.4.1 splitting resistance but modified based on strut-and-tie modeling developed by Davis, Buckner and Ozyildirimon (Dunkman et al. 2009).
 
The bursting and spalling resistance (Pr) at the service limit state shall meet both of the following:
 
:Within h/3 from the end of beam:
:''P<sub>r</sub>'' = ''f<sub>s</sub>A<sub>s</sub>'' ≥ 0.0375''f<sub>pbt</sub>''
:Within 3h/4 from the end of beam:
:''P<sub>r</sub>'' = ''f<sub>s</sub>A<sub>s</sub>'' ≥ 0.06''f<sub>pbt</sub>''
 
Where:
:''f<sub>s</sub>'' = Stress in mild steel not exceeding 20 ksi
:''A<sub>s</sub>'' = Total area of vertical reinforcement within specified distances; where h is overall beam height.
:''f<sub>pbt</sub>'' = Prestressing force immediately prior to transfer
 
'''Confinement Reinforcement'''
 
In accordance with LRFD Article 5.9.4.4.2 confinement reinforcement is not required for box beams and voided and solid slab beams. Rather the provided top and bottom transverse reinforcement shall be anchored into the web of the beam.
 
===751.21.2.3 Temporary Tensile Stress Reinforcement===
The #5-A1 and #4-A2 bars shall resist the tensile force in a cracked section computed on the basis of an uncracked section.
 
Required Steel Area: A1 + A2 = ''T<sub>f</sub>/f<sub>s</sub>
 
Where:
:''f<sub>s</sub>'' = 0.5fy ≤ 30 ksi, allowable tension stress of mild steel, (ksi)
:''T<sub>f</sub>'' = Resultant of total tensile force computed on the basis of an uncracked section, (kips)
 
Designer shall verify the A2 bars are actually in tension before including them in the check. Additional A1 bars may be needed where there isn’t enough deadload to put the top of the beam into compression.
 
Reinforcement shall be designed and spliced using f’ci in accordance with [[751.5 Structural Detailing Guidelines#751.5.9.2.8 Development and Lap Splices|EPG 751.5.9.2.8 Development and Lap Splices]].
 
===751.21.2.4 Limiting Tensile Stresses===
For prestressed beams made continuous and where the A1 and A2 reinforcement is proportioned as stated above:
 
The limiting tensile stress after losses at the top of beams near interior supports is
 
0.24√f’c …(Service III)
 
The above stress limit shall be checked even though the PS beam is designed as a reinforced concrete member at regions of negative flexure.
 
 
The limiting tensile stress after losses near the midspan of beams is
 
0.19√f’c ≤ 0.6 ksi …(Service III)
 
 
The limiting tensile stress before losses at the top of beams is
 
0.24√f’ci
 
 
 
===751.22.2.3 Flexure===
Flexure capacity of girders shall be determined as the following.
 
'''Flexural resistance at strength limit state'''<br/>
 
<math>\,M_r = \phi M_n \ge M_u</math>
 
Where:
{|border="0" cellpadding="5"
|<math>\,M_r</math>||=||Flexural resistance
|-
|-
|<math>\,M_n</math>||=||Nominal flexural resistance
|colspan="3"|'''For LFD Design'''
|-
|-
|<math>\,M_u</math>||=||Total factored moment from Strength I load combination
|colspan="3"|Use "Design Bearing" for load bearing pile and spread footing and use "Design Side Friction + Design End Bearing" for rock socket (drilled shaft).
|-
|-
|valign="top"|<math>\, \phi</math>
|colspan="3"|'''For LRFD Design'''
|valign="top"|=
|Flexural resistance factor as calculated in LRFD 5.5.4.2
|}
 
 
'''Negative moment reinforcement design'''
 
P/S I-girder shall be designed as a reinforced concrete section at regions of negative flexures (i.e., negative moments).
 
At least one-third of the total tensile reinforcement provided for negative moment at the support shall have an embedment length beyond the point of inflection not less than the specified development length of the bars used.
 
Slab longitudinal reinforcement that contributes to making the precast beam continuous over an intermediate bent shall be anchored in regions of the slab that can be shown to be crack-free at strength limit states.  This reinforcement anchorage shall be staggered.  Regular longitudinal slab reinforcement may be utilized as part of the total longitudinal reinforcement required.
 
 
'''Effective Slab Thickness '''
 
An effective slab thickness shall be used for design by deducting from the actual slab thickness a 1” integral, sacrificial wearing surface.
 
 
<div id="Design A1 reinforcement in the top flange"></div>
 
'''Design A1 reinforcement in the top flange '''
 
The A1 reinforcement shall resist the tensile force in a cracked section computed on the basis of an uncracked section.
 
For I girders and bulb-tee girders, A1 reinforcement shall consist of deformed bars (minimum #5 for Type 2, 3 and 4 and minimum #6 for Type 6, 7 and 8).
 
For NU girders, A1 reinforcement shall consist of the four 3/8-inch diameter reinforcement support strands with deformed bars added only as needed. The WWR in the top flange shall not be used for A1 reinforcement because there is insufficient clearance to splice the WWR.
 
See guidance on [https://www.modot.org/bridge-standard-drawings Bridge Standard Drawings (Prestressed I-Girders - PSI)] for required lap lengths, if required.
 
 
Required steel area is equal to:
 
<math>\,A1=\frac{T_t}{f_s}</math>
 
Where:
{|
|<math>\, f_s</math>||= <math>\, 0.5 f_y \le 30 KSI</math>, allowable tensile stress of mild steel, (ksi)
|-
|-
|<math>T_t</math>||= Resultant of total tensile force computed on the basis of an uncracked section, (kips)
|colspan="3"|Use "Minimum Nominal Axial Compressive Resistance" for load bearing pile, "Minimum Nominal Bearing Resistance" for spread footing and "Minimum Nominal Axial Compressive Resistance (Side Resistance + Tip Resistance)" for rock socket (drilled shaft).
|}
|}


'''Shallow Footings '''


'''Limits for reinforcement'''
'''(E2.10) (Use when shallow footings are specified on the Design Layout.)'''


The following criteria shall be considered only at composite stage.
:In no case shall footings of Bents No. <u> &nbsp;  &nbsp;  &nbsp;  </u> and <u> &nbsp;  &nbsp;  &nbsp;  </u> be placed higher than elevations shown <u> &nbsp;  &nbsp;  &nbsp;  </u> and  <u> &nbsp;  &nbsp;  &nbsp;  </u>, respectively.


Minimum amount of prestressed and non-prestressed tensile reinforcement shall be so that the factored flexural resistance, ''M<sub>r''</sub>, is at least equal to the lesser of:<br/>
'''Driven Piles'''


::1) M<sub>cr</sub> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; LRFD Eq. 5.6.3.3-1
'''(E2.20) (Use when prebore is required and the natural ground line is not erratic.)'''
::2) 1.33M<sub>u</sub>
:Prebore for piles at Bent(s) No.<u> &nbsp;  &nbsp;  &nbsp;  </u> and <u> &nbsp; &nbsp;  &nbsp; </u> to elevation(s) <u> &nbsp; &nbsp; &nbsp; </u> and <u> &nbsp;  &nbsp;  &nbsp;  </u>, respectively.


Where:
'''(E2.21) (Use when prebore is required and the natural ground line is erratic.)'''
{|border="0" cellpadding="5"
:Prebore to natural ground line.
|-
<div id="(E2.22) (Use the following note"></div>
|M<sub>cr</sub>||=||Cracking moment, (kip-in.)
|-
|M<sub>u</sub> ||=||Total factored moment from Strength I load combination,  (kip-in.)
|}


'''(E2.22)  (Use when estimated maximum scour depth (elevation) for CIP piles is required.)  '''
:Estimated Maximum Scour Depth (Elevation) shown is for verifying <u>Minimum Nominal Axial Compressive Resistance</u> <u>Design Bearing</u> using dynamic testing only where pile resistance contribution above this elevation shall not be considered.


'''Limiting tensile stress'''
'''(E2.23) (Use when static test piles are required.) The number of piles in table should not include probe piles. If probe piles are specified, place an * beside the number of piles at the bents indicated.'''
 
:&nbsp;*One concrete probe pile shall be driven in permanent position, one for each bent, at Bents No. <u> &nbsp;  &nbsp;  &nbsp;  </u> and <u> &nbsp;  &nbsp;  &nbsp;  </u>.
For prestressed girders made continuous and where the A1 reinforcement is proportioned as stated above:
'''(E2.24) '''
:All piles shall be galvanized down to the minimum galvanized penetration (elevation).


The limiting tensile stress after losses at the top of girders near interior supports is
'''(E2.25) (Use for all HP pile and when pile point reinforcement is required for CIP pile.)'''
:Pile point reinforcement need not be galvanized. Shop drawings will not be  required for pile point reinforcement.
<div id="(E2.26)"></div>
'''(E2.26) (Use for LFD piling design when Design Bearing is determined from service loads and shown on the plans. See guidance on <font color="purple">[MS Cell] (E2.1)</font color="purple"> for specific pile driving verification method. Example: Considered only for widenings, repairs and rehabilitations.) '''


0.24√f’c …(Service III)
:All  piling shall be driven to a minimum nominal axial compressive resistance equal to <u>3.5</u> <u>2.75</u> <u>2.25</u> <u>2.00</u> times the Design Bearing as shown on the plans.
<div id="(E2.27)"></div>
'''(E2.27) Use for galvanized piles.'''


The above stress limit shall be checked even though the PS girder is designed as a reinforced concrete member at regions of negative flexure.
:The contractor shall make every effort to achieve the minimum galvanized penetration (elevation) shown on the plans for all piles.  Deviations in penetration less than 5 feet of the minimum will be considered acceptable provided the contractor makes the necessary corrections to ensure the minimum penetration is achieved on subsequent piles.


'''(E2.28) Use when WEAP is specified as the pile driving criteria for friction pile. Place an * behind each instance of WEAP in the Foundation Data table. The pay item Pile Wave Analysis shall not be included when this note is used.'''


The limiting tensile stress after losses near the midspan of girders is
:<nowiki>*</nowiki>See electronic deliverables file for pile driving inspector’s chart(s). MoDOT will provide alternate charts for different driving systems as needed per request. With the request, the contractor shall provide the hammer manufacturer make and model, and any modifications to the manufacturer’s recommended settings including hammer cushion information. The contractor shall provide the request 30 calendar days before pile driving operations begin.


0.19√f’c ≤ 0.6 ksi …(Service III)
='''REVISION REQUEST 4151'''=


====127.2.3.3.1 Missouri Unmarked Human Burials Law====
If human skeletal remains are encountered during construction, their treatment will be handled in accordance with [https://revisor.mo.gov/main/OneChapter.aspx?chapter=194 Sections 194.400 to 194.410, RSMo], as amended. When human remains are encountered, the Contractor shall first stop all work within a 330-ft. or 100-meter radius of the remains, and secondly, shall notify the MoDOT Construction Inspector and/or Resident Engineer who will contact the Historic Preservation section. Historic Preservation staff will in turn notify the local law enforcement (to ensure that it is not a crime scene) and the State Historic Preservation Office (SHPO) as per RSMo 194 or to notify SHPO what has occurred and that it is covered by Missouri’s Cemeteries Law, §§ 214. RSMo. If the contractor is unable to contact appropriate MoDOT staff, the contractor shall initiate the involvement by local law enforcement and the SHPO. A description of the contractor’s actions will be promptly made to MoDOT.


The limiting tensile stress before losses at the top of girders is
If the human remains are prehistoric, the agency must consult with Indian tribes who have with ancestral, historic, and ceded land connections to the area in which the remains are located to determine the appropriate treatment of the remains. [http://www.modot.org/ehp/TribalMap.htm Tribal consultation] may result in the conclusion that the remains should be preserved in place and construction plans changed to facilitate their preservation.


0.24√f’ci
<br><br>
<hr style="border:none; height:2px; background-color:red;" />
<br><br>


==127.2.9 Construction Inspection Guidance==
Mitigation by data recovery is usually completed prior to construction if the presence of cultural resources is known. If [http://epg.modot.org/index.php/127.2_Historic_Preservation_and_Cultural_Resources#127.2.8_Artifacts_and_Features artifacts] are discovered during construction activities, the Historic Preservation section must be immediately notified. This will allow an inspection of the site by MoDOT HP staff to determine if further investigation is necessary before construction activities continue.


[http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=4 Sec. 107.8.2] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=5 Sec. 203.4.8] of the ''Missouri Standard Specifications for Highway Construction'' require the contractor to take steps to preserve any such artifacts that may be encountered and to notify the MoDOT Construction Inspector or Resident Engineer of their presence. If it is necessary to discontinue operations in a particular area to preserve such objects, this section of the specifications is basis for a work suspension. In order to ensure compliance with applicable state laws, the MoDOT Construction Inspector or Resident Engineer cannot release remains or artifacts or allow the contractor to disturb the area within the 330-foot or 100-meter buffer space around these discovered items, until after consultation with MoDOT HP staff and until after all applicable requirements from FHWA or SHPO have been addressed.


===127.2.9.1 Cultural Resources Encountered During Construction===
If cultural resources are encountered during construction, the contractor shall immediately stop all work within a 330-foot or 100-meter buffer around the limits of the resource and shall not resume without specific authorization from a MoDOT Historic Preservation Specialist. The contractor shall notify the MoDOT Resident Engineer or Construction Inspector, who shall contact the MoDOT HP within 24 hours of the discovery. MoDOT HP shall contact FHWA and SHPO within 48 hours of learning of the discovery and provide an evaluation of the resource and reasonable efforts to see if it can be avoided. FHWA shall make an eligibility and effects determination based upon the preliminary evaluation and consul with MoDOT, and SHPO a minimize or mitigate any adverse effect. FHWA will notify the Council and any tribes that might attach religious and/or cultural significance to the property within 48 hours of this determination. FHWA shall take into account Council and Tribal recommendations regarding the eligibility of the property and proposed actions, and direct MoDOT to carry out the appropriate actions. MoDOT will provide FHWA and SHPO with a report of the actions when they are completed. FHWA shall provide this report to the council and the tribes.


----
===127.2.9.2 Human Remains Encountered During Construction===
If human remains are encountered during construction, the contractor shall immediately stop all work within a 330-foot or 100-meter radius of the remains and shall not resume without specific authorization from MoDOT HP Staff, and either the SHPO or the local law enforcement officer, whichever party has jurisdiction over and responsibility for such remains. The contractor shall notify the MoDOT Construction Inspector and/or Resident Engineer who will contact the MoDOT HP section within 24 hours of the discovery. MoDOT HP staff will immediately notify the local law enforcement (to ensure that it is not a crime scene) and the SHPO as per RSMo 194 or to notify SHPO what has occurred and that it is covered by Missouri’s Cemeteries Law, §§ 214. RSMo. MoDOT HP staff will notify FHWA that human remains have been encountered within 24 hours of being notified of the find. If, within 24 hours, the contractor is unable to contact appropriate MoDOT staff, the contractor shall initiate the involvement by local law enforcement and the SHPO. A description of the contractor’s actions will be promptly made to MoDOT. FHWA will notify any Indian tribe that might attach cultural affiliation to the identified remains as soon as possible after their identification. FHWA shall take into account Tribal recommendations regarding treatment of the remains and proposed actions, and then direct MoDOT HP to carry-out the appropriate actions in consultation with the SHPO. MoDOT shall monitor the handling of any such human remains and associated funerary objected, sacred object or objects of cultural patrimony in accordance with the Missouri Unmarked Human Burial Sites Act, §§ 194.400 – 194.410, RSMo.

Latest revision as of 16:04, 3 February 2026

REVISION REQUEST 4036

106.3.2.93.1 Means of Evaluating Aggregate Alkali Carbonate Reactivity

1. Chemical Analysis

The chemical analysis of aggregate reactivity is an objective, quantifiable and repeatable test. MoDOT will perform the chemical analysis per the process identified in ASTM C 25 for determining the aggregate composition. The analysis determines the calcium oxide (CaO), magnesium oxide (MgO), and aluminum oxide (Al2O3) content of the aggregate. The chemical compositions are then plotted on a chart with the CaO/MgO ratio on the y-axis and Al2O3 percentage on the x-axis per Fig. 2 in AASHTO R 80. Aggregates are considered potentially reactive if the Al2O3 content is greater than or equal to 1.0% and the CaO/MgO ratio is either greater than or equal to 3.0 or less than or equal to 10.0 (see chart below). See flow charts in 106.3.2.93.2 for approval hierarchy. CaO, MgO and Al2O3 shall be analyzed by instrumental analysis only.

* MoDOT’s upper and lower limits of potentially reactive (shaded area) aggregates.

2. Petrographic Examination

A petrographic examination is another means of determining alkali carbonate reactivity. The sample aggregate for petrographic analysis will be obtained at the same time as the source sample. MoDOT personnel shall be present at the time of sample. The petrographic sample shall be placed in an approved tamper-evident container (provided by the quarry) for shipment to petrographer. Per ASTM C 295, a petrographic examination is to be performed by a petrographer with at least 5 years of experience in petrographic examinations of concrete aggregate including, but not limited to, identification of minerals in aggregate, classification of rock types, and categorizing physical and chemical properties of rocks and minerals. The petrographer will have completed college level course work in mineralogy, petrography, or optical mineralogy. MoDOT does not accept on-the-job training by a non-degreed petrographer as qualified to perform petrographical examinations. MoDOT may request petrographer’s qualifications in addition to the petrographic report. The procedures in C 295 shall be used to perform the petrographic examination. The petrographic examination report to MoDOT shall include at a minimum:

  • Quarry name and ledge name; all ledges if used in combination
  • MoDOT District quarry resides
  • Date sample was obtained; date petrographic analysis was completed
  • Name of petrographer and company/organization affiliated
  • Lithographic descriptions with photographs of the sample(s) examined
  • Microphotographs of aggregate indicating carbonate particles and/or other reactive materials
  • Results of the examination
  • All conclusions related to the examination

See flow charts in EPG 106.3.2.93.2 for the approval hierarchy. See EPG 106.3.2.93.3 for petrographic examination submittals. No direct payment will be made by the Commission for shipping the petrographic analysis sample to petrographer, or for the petrographic analysis performed by the petrographer.

3. Concrete Prism/Beam Test

ASTM C 1105 is yet another means for determining the potential expansion of alkali carbonate reactivity in concrete aggregate. MoDOT will perform this test per C 1105 at its Central Laboratory. Concrete specimen expansion will be measured at 3, 6, 9, and 12 months. The test specimens will be considered alkali carbonate reactive (expansive) if the specimens expand greater than 0.015% at 3 months, 0.025% at 6 months, or 0.030% at 12 months. See flow chart in EPG 106.3.2.93.2 for the approval hierarchy.


REVISION REQUEST 4143

751.36.5 Design Procedure

  • Structural Analysis
  • Geotechnical Analysis
  • Drivability Analysis

751.36.5.1 Design Procedure Outline

  • Determine foundation load effects from the superstructure and substructure for Service, Strength and Extreme Event Limit States.
  • If applicable, determine scour depths, liquefaction information and pile design unbraced length information.
  • Determine if downdrag loadings should be considered.
  • Select preliminary pile size and pile layout.
  • Perform a Static Pile Soil Interaction Analysis. Estimate Pile Length and pile capacity.
  • Based on pile type and material, determine Resistance Factors for Structural Strength (ϕc and ϕf).
  • Determine:
    • Maximum axial load effects at toe of a single pile
    • Maximum combined axial & flexural load effects of a single pile
    • Maximum shear load effect for a single pile
    • Uplift pile reactions
  • Determine Nominal and Factored Structural Resistance for single pile
    • Determine Structural Axial Compression Resistance
    • Determine Structural Flexural Resistance
    • Determine Structural Combined Axial & Flexural Resistance
    • Determine Structural Shear Resistance
  • Determine method for pile driving acceptance criteria
  • Determine Resistance Factor for Geotechnical Resistance (ϕstat) and Driving Resistance (ϕdyn).
  • If other than end bearing pile on rock or shale, determine Nominal Axial Geotechnical Resistance for pile.
  • Determine Factored Axial Geotechnical Resistance for single pile.
  • Determine Nominal pullout resistance if pile uplift reactions exist.
  • Check for pile group effects.
  • Resistance of Pile Groups in Compression
  • Check Drivability of all pile (bearing and friction pile) using the Wave equation analysis.
  • Review Static Pile Soil Interaction Analysis and pile lengths for friction pile.
  • Show proper Pile Data on Plan Sheets (Foundation Data Table).

751.36.5.2 Structural Resistance Factor (ϕc and ϕf) for Strength Limit State

LRFD 6.5.4.2

For integral end bent simple pile design, use Φc = 0.35 for CIP steel pipe piles and HP piles. See Figure 751.35.2.4.2.

For pile at all locations where integral end bent simple pile design is not applicable, use the following:

The structural resistance factor for axial resistance in compression is dependent upon the expected driving conditions. When the pile is subject to damage due to severe driving conditions where use of pile point reinforcement is necessary:
Steel Shells (Pipe): ϕc= 0.60
HP Piles: ϕc= 0.50
When the pile is subject to good driving conditions where use of pile point reinforcement is not necessary:
Steel Shells (Pipe) Piles: ϕc= 0.70
HP Piles: ϕc= 0.60
For HP piles, pile point reinforcement is always required when HP piles are anticipated to be driven to rock and proofed. Driving HP piles to rock is considered severe driving conditions for determination of structural resistance factor. However, driving HP piles through overburden not likely to impede driving to deep rock or preboring to rock for setting piles are two situations that could be considered as less than severe. Further, driving any steel pile through soil without rubble, boulders, cobbles or very dense gravel could be considered good driving conditions for determination of structural resistance factor. Consult the Structural Project Manager or Structural Liaison Engineer.
The structural resistance factor for combined axial and flexural resistance of undamaged piles:
Axial resistance factor for HP Piles: ϕc= 0.70
Axial resistance for Steel Shells (Pipe): ϕc= 0.80
Flexural resistance factor for HP Piles or Steel Shells: ϕf= 1.00
For Extreme Event Limit States, see LRFD 10.5.5.3.

751.36.5.3 Geotechnical Resistance Factor (ϕstat) and Driving Resistance Factor (ϕdyn)

The factors for Geotechnical Resistance (ϕstat) and Driving Resistance (ϕdyn) may be different because of the reliability of the different methods used to determine the nominal bearing resistance. Caution should be used if the difference in factors for Geotechnical Resistance and Driving Resistance are great as it can lead to issues with pile overruns. Also see EPG 751.36.5.9.

Geotechnical Resistance Factor, ϕstat:

The Geotechnical Resistance factor is based on the static method used by the designer in determining the nominal bearing resistance. Unlike the Driving Resistance factor the Geotechnical Resistance factor can vary with the soil layers. If Geotechnical Resistance factors are not provided by the Geotechnical Engineer, the static method and resistance factors shall be selected from the table below. The values provided in LRFD Table 10.5.5.2.3-1 are only applicable if the end of drive criteria is based off the total pile penetration which is not recommended. For Extreme Event Limit States see LRFD 10.5.5.3.

Table - Static Analysis Resistance Factors used for Pile Length Estimates
Pile Type Soil Type Static Analysis Method Side Friction1
ϕstat		 End Bearing
ϕstat
CIP Piles - Steel Pipe Shells Clay Alpha - Tomlinson ϕdyn2 ϕdyn2
Sand Nordlund3 0.45 - Gates
0.45 - WEAP
0.55 - PDA		 0.45 - Gates
0.45 - WEAP
0.55 - PDA
LCPC4 0.70 0.45
Schmertmann5 0.50 0.50
1 For mixed soil profiles the lowest applicable resistance factor for clay or sand may be used to simplify the analysis.
2 ϕdyn = see following section.
3The Nordlund method is recommended for sand layers in mixed soil profiles where CPT data is not available.
4The resistance factors associated with the LCPC method are not statistically calibrated for reliability, but studies have shown this method to be one of the most reliable methods for predicting soil behavior from CPT data.
5Per LRFD 10.7.3.8.6g the Schmertmann method shall only be used for sands and nonplastic silts with CPT data.
For more detailed guidance see SEG 25-001 New Policy for Friction Pile.

Driving Resistance Factor, ϕdyn:

The Driving Resistance factor shall be selected from LRFD Table 10.5.5.2.3-1 based on the method to be used in the field during construction to verify nominal axial compressive resistance.

Pile Driving Verification Method Resistance Factor,
ϕdyn
FHWA-modified Gates Dynamic Pile Formula
(End of Drive condition only)		 0.40
Wave Equation Analysis (WEAP) 0.50
Dynamic Testing (PDA) on 1 to 10% piles 0.65
Other methods Refer to LRFD Table 10.5.5.2.3-1

Use EPG 751.50 Standard Detailing Note G7.3 on plans as required for end bearing piles driven to rock. This requirement shall apply to any type of rock meaning weak to strong rock including stronger shales where HP piling is anticipated to meet refusal. The verification method shown on the plans is only used to verify the nominal axial compressive resistance prior to reaching practical refusal. If the practical refusal criterion is met the field verification method shown on the plans is no longer considered valid.

For end bearing piles tipped in shale, sandstone, or rock of uncertain strength at any loading where the likelihood of pile damage is increased, the Foundation Investigation Geotechnical Report (FIGR) should give a recommendation for dynamic pile testing (PDA) or no PDA. For most end bearing piles, where a recommendation for field verification is not given in the FIGR, the designer will need to determine whether gates or WEAP is required for the pile driving verification method based on the loading demands on the pile or other factors.

For piles bearing on hard rock with MNACR less than 600 kips, FHWA-modified Gates Dynamic Pile Formula should be listed as verification method, and practical refusal criterion should control end of driving criteria. FHWA-modified Gates Dynamic Pile Formula is not considered accurate for pile loading (Minimum Nominal Axial Compressive Resistance) exceeding 600 kips. When pile loading exceeds 600 kips, use wave equation analysis, dynamic testing, or other method. Consideration should be given to using additional piles to reduce the MNACR below 600 kips.

Under special circumstances when rock limits or conditions are nonuniform, WEAP should be considered in order to limit pile damage since it requires further scrutiny of the site conditions with the proposed pile driving system.

Dynamic Testing is recommended for projects with friction piles where the soil profile is comprised primarily of sand. For bridges where the soil profile is comprised primarily of clays or evenly mixed clays and sands the recommended verification method is WEAP. When WEAP is specified as the pile driving criteria for friction pile, provide standard note E2.28 below the foundation table. For more detailed guidance see SEG 25-001 New Policy for Friction Pile.

751.36.5.4 Downdrag and Losses to Geotechnical Resistance due to Scour and Liquefaction

Downdrag and Losses to Geotechnical Resistance due to Scour and Liquefaction (kips), LRFD 10.7.3.6, 10.7.3.7, and AASHTO Guide Specifications for LRFD Seismic Bridge Design (SGS) 6.8.

Downdrag, liquefaction and scour all reduce the available skin friction capacity of piles. Downdrag (DD) is unique because it not only causes a loss of capacity, but also applies a downward force to the piles. This is usually attributed to embankment settlement. However, downdrag can also be caused by a non-liquefied layer overlying a liquefied layer. Review geotechnical report for downdrag and liquefaction information.

751.36.5.5 Preliminary Structural Nominal Axial Design Capacity (PNDC) of an individual pile

The PNDC equations provided herein assume the piles are continually braced. This assumption is applicable for the portion of piling below ground or confined by solid wall encasement. If designing a pile bent structure, scour exists or liquefaction exists, then the pile shall be checked considering the appropriate unbraced length.

Structural Steel HP Piles

PNDC=0.66λFyAS
Since we are assuming the piles are continuously braced, then λ= 0.
Fy is the yield strength of the pile
AS is the area of the steel pile

Welded or Seamless Steel Shell (Pipe) Cast-In-Place Piles (CIP Piles)

PNDC=0.85f'cAc+FyAst
Fy is the yield strength of the pipe pile
Ast is the area of the steel pipe (deducting 12.5 % ASTM tolerance and 1/16 inch corrosion where appropriate.)
f'c is the concrete compressive strength at 28 days
Ac is the area of the concrete inside the pipe pile
Maximum Load during pile driving = 0.90(fyAst)

Welded or Seamless Steel Shell shall be ASTM A252 Modified Grade 3 (50 ksi). ASTM A252 states “the wall thickness at any point shall not be more than 12.5% under the specified nominal wall thickness.” AASHTO recommends deducting 1/16” of the wall thickness due to corrosion (LRFD 5.13.4.5.2). Corrosion need not be considered at construction stage and for drivability analysis and static analysis. For drivability analysis and static analysis deduct 12.5% of specified nominal wall thickness (ASTM A252). For structural design deduct 12.5 % (ASTM A252) and 1/16” for corrosion (LRFD 5.13.4.5.2) from specified nominal wall thickness.

751.36.5.6 Preliminary Factored Axial Design Capacity (PFDC) of an Individual Pile

PFDC = Structural Factored Axial Compressive Resistance – Factored Downdrag Load

751.36.5.7 Design Values for Steel Pile

751.36.5.7.1 Integral End Bent Simple Pile Design

The following design values may be used for integral end bents where the simple pile design method is applicable per EPG 751.35.2.4.2 Pile Design. These values are not applicable for soils subject to liquefaction or scour where unbraced lengths may alter the design.

751.36.5.7.1.1 Design Values for Individual HP Pile

Fy = 50 ksi. End Bearing Piles (HP piles) anticipated to be driven to rock.

Pile Size As
Area,
sq. in.		 Structural
Nominal
Axial
Compressive
Resistance
PNDC1,2,
kips		 Φc
Structural
Resistance
Factor4,5,
LRFD 6.5.4.2		 Structural
Factored
Axial
Compressive
Resistance2,3,4,
kips		 0.9*ϕda*Fy
Maximum
Nominal
Driving
Stress,
LRFD 10.7.8,
ksi
HP 12x53 15.5 775 0.35 271 45.00
HP 14x73 21.4 1070 0.35 375 45.00
1 Structural Nominal Axial Compressive Resistance for fully embedded piles only.

     Minimum Nominal Axial Compressive Resistance = Required nominal driving resistance, Rndr
                  = (Maximum factored axial loads / ϕdyn) ≤ Structural nominal axial compressive resistance, PNDC          LRFD 10.5.5.2.3

2 Axial Compressive Resistance values shown above shall be reduced when downdrag is considered.

3 Maximum factored axial load per pile ≤ Structural factored axial compressive resistance.

4 Values are applicable for Strength Limit States.

5 Use (Φc) = 0.35 instead of 0.5 for structural resistance factor (LRFD 6.5.4.2)


Notes:

ϕdyn = Resistance factor of the dynamic method to be used to estimate nominal pile resistance during pile installation.      LRFD Table 10.5.5.2.3-1

For more information about selecting pile driving verification methods refer to EPG 751.36.5.3 Geotechnical Resistance Factor (ϕstat) and Driving Resistance Factor (ϕdyn).

Drivability analysis shall be performed for all HP piles using Delmag D19-42. Do not show minimum hammer energy on plans.

Check drivability for all HP Pile in accordance with EPG 751.36.5.11

For additional design requirements, see EPG 751.36.5.1.

751.36.5.7.1.2 Design Values for Individual Cast-In-Place (CIP) Pile

Modified Grade 3 Fy = 50 ksi; F'c = 4 ksi; Structural Axial Compressive Resistance Factor, (Φc)1,3 = 0.35

Unfilled Pipe For Axial Analysis2
Pile Outside Diameter O.D., in. Pile Inside Diameter I.D., in. Minimum Wall Thickness, in. Reduced Wall thick. for Fabrication (ASTM A252), in. As,4
Area
of
Steel
Pipe,
sq. in.		 Structural
Nominal
Axial
Compressive
Resistance
Pn5,6,7,
kips		 Structural
Factored Axial
Compressive
Resistance1,7,8,
kips		 0.9*ϕda*Fy*As
Maximum
Nominal
Driving
Resistance6,
LRFD 10.7.8,
kips
14 13 0.5 0.44 18.47 923 323 831
12.75 0.6259 0.55 22.84 1142 400 1028
16 15 0.5 0.44 21.22 1061 371 955
14.75 0.6259 0.55 26.28 1314 460 1183
20 19 0.5 0.44 26.72 1336 468 1202
18.75 0.625 0.55 33.15 1658 580 1492
24 23 0.5 0.44 32.21 1611 564 1450
22.75 0.625 0.55 40.03 2001 700 1801
22.5 0.75 0.66 47.74 2387 835 2148

1Values are applicable for Strength Limit States.

2 Use to determine preliminary number of pile and pile size. For piles predominantly embedded and tipped in cohesionless soils the maximum loads provided in EPG 751.36.5.10 will control.

3 Use (Φc) = 0.35 instead of 0.6 for structural axial compressive resistance factor (LRFD 6.5.4.2). Since ϕdyn >> Φc the maximum nominal driving resistance may not control.

4 Corrosion NOT considered at construction stage and for drivability analysis and static analysis. For drivability analysis and static analysis use reduced pipe nominal wall thickness, 12.5%, for fabrication (ASTM A252).

5 Structural Nominal Axial compressive resistance for fully embedded piles only.

6 Minimum Nominal Axial Compressive Resistance = Required nominal driving resistance, Rndr

                  = Maximum factored axial loads / ϕdyn ≤ Structural nominal axial compressive resistance, Pn and           LRFD 10.5.5.2.3

                  ≤ Maximum nominal driving resistance.

7 Axial Compressive Resistance values shown above shall be reduced when downdrag is considered.

8 Maximum factored axial load per pile ≤ Structural factored axial compressive resistance.

9 5/8” wall thickness is less commonly available than the smaller wall thicknesses of pipe pile.

Notes:

Drivability analysis shall be performed for all CIP piles (unfilled pipe) using Delmag D19-42. Do not show minimum hammer energy on plans.

Check drivability for all CIP Pile in accordance with EPG 751.36.5.11.

Require dynamic pile testing for field verification for all CIP piles on the plans.
ϕdyn = 0.65 = Dynamic Testing resistance factor to be used to estimate nominal pile resistance during pile installation. This value may be increased if static load testing is specified per LRFD Table 10.5.5.2.3-1.

For additional design requirements, see EPG 751.36.5.1.

751.36.5.7.2 General Pile Design

The following design values are recommended for general use where the simple pile design method is not applicable per EPG 751.35.2.4.2 Pile Design. These values are not applicable for soils subject to liquefaction or scour where unbraced lengths may alter the design.

751.36.5.7.2.1 Design Values for Individual HP Pile

Fy = 50 ksi. End Bearing Piles (HP piles) anticipated to be driven to rock.

Pile Size As
Area,
sq. in.		 Structural
Nominal
Axial
Compressive
Resistance
PNDC1,2,
kips		 Φc
Structural
Resistance
Factor4,
LRFD 6.5.4.2		 Structural
Factored
Axial
Compressive
Resistance2,3,4,
kips		 0.9*ϕda*Fy
Maximum
Nominal
Driving
Stress,
LRFD 10.7.8,
ksi
HP 12x53 15.5 775 0.5 388 45.00
HP 14x73 21.4 1070 0.5 535 45.00
1 Structural Nominal Axial Compressive Resistance for fully embedded piles only. Structural Nominal Axial Compressive Resistance for unsupported piles shall be determined in accordance with LRFD 10.7.3.13.1. (i.e., intermediate pile cap bent).

     Minimum Nominal Axial Compressive Resistance = Required nominal driving resistance, Rndr
                  = (Maximum factored axial loads / ϕdyn) ≤ Structural nominal axial compressive resistance, PNDC          LRFD 10.5.5.2.3

2 Axial Compressive Resistance values shown above shall be reduced when downdrag is considered.

3 Maximum factored axial load per pile ≤ Structural factored axial compressive resistance.

4 Values are applicable for Strength Limit States. Modify value for other Limit States.


Notes:

ϕdyn = Resistance factor of the dynamic method to be used to estimate nominal pile resistance during pile installation.      LRFD Table 10.5.5.2.3-1

For more information about selecting pile driving verification methods refer to EPG 751.36.5.3 Geotechnical Resistance Factor (ϕstat) and Driving Resistance Factor (ϕdyn).

Drivability analysis shall be performed for all HP piles using Delmag D19-42. Do not show minimum hammer energy on plans.

Check drivability for all HP Pile in accordance with EPG 751.36.5.11

For additional design requirements, see EPG 751.36.5.1.

751.36.5.7.2.2 Design Values for Individual Cast-In-Place (CIP) Pile

Modified Grade 3 Fy = 50 ksi; F'c = 4 ksi; Structural Resistance Factor, (Φc)1 = 0.6

Unfilled Pipe For Axial Analysis2 Concrete Filled Pipe For Flexural Analysis3
Pile Outside Diameter O.D., in. Pile Inside Diameter I.D., in. Minimum Wall Thickness, in. Reduced Wall thick. for Fabrication (ASTM A252), in. As,4 Area of Steel Pipe, sq. in. Structural Nominal Axial Compressive Resistance, Pn5,6,7, kips Structural Factored Axial Compressive Resistance1,7,8, kips 0.9*ϕda*Fy*As Maximum
Nominal
Driving
Resistance5,6, LRFD 10.7.8, kips		 Reduced Wall Thick. for Corrosion (1/16"), LRFD 5.13.4.5.2, in. Ast,9 Net Area of Steel Pipe, sq. in. Ac Concrete Area, sq. in. Structural Nominal Axial Compressive Resistance PNDC5,7,10, kips Structural Factored Axial Compressive Resistance1,7,10, kips
14 13 0.5 0.44 18.47 923 554 831 0.375 15.76 133 1239 743
12.75 0.62511 0.55 22.84 1142 685 1028 0.484 20.14 128 1441 865
16 15 0.5 0.44 21.22 1061 637 955 0.375 18.11 177 1506 904
14.75 0.62511 0.55 26.28 1314 788 1183 0.484 23.18 171 1740 1044
20 19 0.5 0.44 26.72 1336 801 1202 0.375 22.83 284 2105 1263
18.75 0.625 0.55 33.15 1658 995 1492 0.484 29.27 276 2402 1441
24 23 0.5 0.44 32.21 1611 966 1450 0.375 27.54 415 2790 1674
22.75 0.625 0.55 40.03 2001 1201 1801 0.484 35.36 406 3150 1890
22.5 0.75 0.66 47.74 2387 1432 2148 0.594 43.08 398 3506 2103

1 Values are applicable for Strength Limit States. Modify value for other Limit States.

2 Use to determine preliminary number of pile and pile size. For piles predominantly embedded and tipped in cohesionless soils the maximum loads provided in EPG 751.36.5.10 will control.

3 Pipes placed in prebored holes in rock can use filled pipe capacity for axial plus flexural resistance. Therefore, number of piles should be based on this capacity assuming rock is infinitely more stiff. This recognizes that pile driving is not a concern.

4 Corrosion NOT considered at construction stage and for drivability analysis and static analysis. For drivability analysis and static analysis use reduced pipe nominal wall thickness, 12.5%, for fabrication (ASTM A252).

5 Structural Nominal Axial compressive resistance for fully embedded piles only. Value in table is a raw number and is the value used to determine the factored resistance. Structural Nominal Axial Compressive Resistance for unsupported piles shall be determined in accordance with LRFD 10.7.3.13.1. (i.e. Intermediate pile cap bent).

6 Minimum Nominal Axial Compressive Resistance = Required nominal driving resistance, Rndr

      = Maximum factored axial loads / ϕdyn ≤ Structural nominal axial compressive resistance, Pn and               LRFD 10.5.5.2.3

                                                                    ≤ Maximum nominal driving resistance.

7 Axial Compressive Resistance values shown above shall be reduced when downdrag is considered

8 Maximum factored axial load per pile ≤ Structural factored axial compressive resistance

9 Net area of steel pipe, Ast, assumes a 12.5% fabrication reduction (ASTM A252) and 1/16" (LRFD 5.13.4.5.2) reduction in pipe nominal wall thickness for corrosion.

10 Use for lateral load analysis. Resistance value includes filled pipe based on net area of steel pipe, Ast (12.5% fab. reduction and 1/16” corr. reduction in nominal pipe wall thickness).

11 5/8” wall thickness is less commonly available than the smaller wall thicknesses of pipe pile.

Notes:

Drivability analysis shall be performed for all CIP piles (unfilled pipe) using Delmag D19-42. Do not show minimum hammer energy on plans.

Check drivability for all CIP Pile in accordance with EPG 751.36.5.11.

Require dynamic pile testing for field verification for all CIP piles on the plans.

ϕdyn = 0.65 = Dynamic Testing resistance factor to be used to estimate nominal pile resistance during pile installation. This value may be increased if static load testing is specified per LRFD Table 10.5.5.2.3-1.

For additional design requirements, see EPG 751.36.5.1.

751.36.5.8 Additional Provisions for Pile Cap Footings

Pile Group Layout:

Pu = Total Factored Vertical Load.

Preliminary Number of Piles Required = TotalFactoredVerticalLoadPFDC

Layout a pile group that will satisfy the preliminary number of piles required. Calculate the maximum and minimum factored load applied to the outside corner piles assuming the pile cap/footing is perfectly rigid. The general equation is as follows:

Max. Load =   PuTotalNo.ofPiles+MuxYiΣYi2+MuyXiΣXi2

Min. Load =   PuTotalNo.ofPiles−MuxYiΣYi2−MuyXiΣXi2

The maximum factored load per pile must be less than or equal to PFDC for the pile type and size chosen. If not, the pile size must be increased or additional piles must be added to the pile group. Reanalyze until the pile type, size and layout are satisfactory.


Pile Uplift on End Bearing Piles and Friction Piles:

Service - I Limit State:
Minimum factored load per pile shall be ≥ 0.
Tension on a pile is not allowed for conventional bridges.
Strength and Extreme Event Limit States:
Uplift on a pile is not preferred for conventional bridges.
Maximum Pile Uplift load = │Minimum factored load per pile│ - │Factored pile uplift resistance│ ≥ 01
Note: Compute maximum pile uplift load if value of minimum factored load is negative.
1 The minimum factored load (maximum tensile load) per pile should preferably not result in uplift for the Strength and Extreme Event Limit States. Pile uplift for the Strength and Extreme Event limit states may be permitted by SPM or SLE based on infrequent uplift load cases and small magnitudes of uplift. This decision is based on the presumed difficulty of a pile cap footing to rotate, specifically for it to be able to rotate on piles driven to rock. When pile uplift is allowed, the necessity of top pile cap reinforcement shall be investigated and the standard anchorage detail for HP pile per EPG 751.36.4.1 Structural Steel HP Pile - Details shall be used.


Resistance of Pile Groups in Compression                                                                                                                          LRFD 10.7.3.9

If the cap is not in firm contact with the ground and if the soil at the surface is soft, the individual nominal resistance of each pile (751.36.5.5) shall be multiplied by an efficiency factor, η, based on pile spacing.

751.36.5.9 Estimate Pile Length and Check Pile Capacity

751.36.5.9.1 Estimated Pile Length

Friction Piles:

Estimate the pile length required to achieve the minimum nominal axial compressive resistance, MNACR, or required driving resistance, Rndr, for establishment of contract pile quantities. Perform a static analysis using one of the methods given in EPG 751.36.5.3 Geotechnical Resistance Factor (ϕstat) and Driving Resistance Factor (ϕdyn) to determine the nominal resistance profile of the soil. For each soil layer the appropriate resistance factor, ϕstat, shall be applied to account for the reliability of the static analysis method to create a factored resistance profile. The penetration depth would then occur at the location where the factored resistance profile intercepts the factored load. The relationship between the static axial compressive resistance and required driving resistance for a uniform soil profile with a constant static resistance factor is given as follows:

ϕdyn x Rndr = ϕstat x Rnstat ≥ Factored Load LRFD C10.7.3.3-1

Where:

ϕdyn = see EPG.751.36.5.3
Rndr = Required nominal driving resistance = MNACR
ϕstat = Static analysis resistance factor per EPG 751.36.5.3 or as provided by the Geotechnical Engineer. Factors for side friction and end bearing may be different.
Rnstat = Required nominal static resistance

Use soil profiles from borings and mimic soil characteristics as closely as possible in computations or software to calculate the geotechnical resistance and for estimating the length of pile. For more detailed guidance see SEG 25-001 New Policy for Friction Pile.

It is not advisable to design pile deeper than available borings or to reach capacity within the bottom 3 to 5 feet of borings. If a longer pile depth is needed to meet design requirements then request Geotechnical Section to provide deeper borings or increase the number of piles which will reduce load per pile as well as the required pile length.

For friction pile the top five feet of soil friction resistance may be neglected with SPM or SLE approval for possible disturbance from MSE wall excavation prior to driving pile.

End Bearing Piles:

The estimated pile length is the distance along the pile from the cut-off elevation to the estimated tip elevation considering any penetration into rock. The estimated tip elevation shall not be shown on plans for end bearing piles.

The geotechnical material above the estimated end bearing tip elevation shall be reviewed for the presence of glacial till or similar layers. If these layers are present, then a static analysis shall be performed to verify if the required pile resistance is reached at a higher elevation due to pile friction capacity.

751.36.5.9.2 Check Pile Geotechnical Capacity (Axial Loads Only)

Use the same methodology outlined in EPG 751.36.5.9.1 Estimated Pile Length.

751.36.5.9.3 Check Pile Structural Capacity (Combined Axial and Bending)

Structural design checks which include lateral loading and bending shall be accomplished using the appropriate structural resistance factors.

751.36.5.10 Pile Nominal Axial Compressive Resistance

The minimum nominal axial compressive resistance, MNACR, or required driving resistance, Rndr, must be calculated and shown on the final plans. The factored axial compressive resistance will be used to verify the pile group layout and loading. The minimum nominal axial compressive resistance will be used in construction field verification methods to obtain the required nominal driving resistance.

Minimum Nominal Axial Compressive Resistance, MNACR = Required Nominal Driving Resistance, Rndr
= Maximum factored axial loads/ϕdyn
ϕdyn = Resistance factor of the dynamic method used to estimate nominal pile resistance during pile installation. LRFD 10.5.5.2.3.1

The value of Rndr shown on the plans shall be the greater of the value required at the Strength limit state and Extreme Event limit state. This value shall not be greater than the structural nominal axial compressive resistance of the steel HP pile nor shall it exceed the maximum nominal driving resistance of the steel shell for CIP piles. See EPG 751.36.5.5.              LRFD 10.7.7

For friction piles predominantly embedded and tipped in cohesionless soils the minimum nominal axial compressive resistance shall be limited to the values shown in the following table. Approval from the SPM, SLE or owner's representative is required before exceeding the limits provided in this table.

Maximum Axial Loads for Friction Pile in Cohesionless Soils
Pile Type Minimum Nominal
Axial Compressive
Resistance (Rndr)1
(kips)
 Maximum Factored Axial Load (kips)
Dynamic Testing Wave Equation
Analysis		 FHWA-modified
Gates Dynamic
Pile Formula
ϕdyn= 0.65 ϕdyn = 0.50 ϕdyn = 0.40
CIP 14” 210 136 105 84
CIP 16” 240 156 120 96
CIP 20” 300 195 150 120
CIP 24” 340 221 170 136
1 The minimum nominal axial compressive resistance values are correlated to match the maximum design tonnage values used in past ASD practice. A factor of safety of 3.5 is used to determine the equivalent Rndr.

751.36.5.11 Check Pile Drivability

Drivability of the pile through the soil profile shall be investigated using the GRLWEAP wave equation analysis program. The static axial compressive resistance profile used in the wave equation analysis shall be determined using one of the approved static methods given in EPG 751.36.5.3.

Drivability analysis shall be performed by the designer for all pile types (bearing pile and friction pile) using the Delmag D19-42 hammer with manufacturer recommendations. The drivability analysis shall confirm that the pile can be driven to the minimum tip elevation, rock elevation or reach the minimum nominal axial compressive resistance prior to refusal and without overstressing the pile. If the drivability analysis shows overstress or refusal prior to reaching the desired depth a lighter or heavier hammer from the table below may be used to confirm constructability. The drivability analysis is not intended to confirm that a pile can be driven through rock (shales, sandstones, etc…) where the likelihood of pile damage is increased and PDA is recommended to reduce loads and monitor pile stresses in the field. The drivability analyses performed by the designer does not waive the responsibility of the contractor in selecting the appropriate pile driving system per Sec 702.3.5 (also discussed below).

Use soil profiles from borings and mimic soil characteristics as closely as possible for computations or in software to perform drivability analysis of any kind of pile.

Structural steel HP Pile:

Drivability analysis shall be performed for the box shape of the pile (i.e., not the perimeter).

Drivability shall be performed considering existing condition without considering any excavation/ disturbance (i.e., possible disturbance to top 5 feet of soil from MSE wall excavation prior to driving pile), liquefaction or future scour loss.

Hammer types:

Pile Driving Hammer Information For GRLWEAP
Hammer used in the field per survey response (2017)
GRLWEAP ID Hammer name No. of Responses
41 Delmag D19-421 13
40 Delmag D19-32 6
38 Delmag D12-42 4
139 ICE 32S 4
15 Delmag D30-32 2
Delmag D25-32 2
127 ICE 30S 1
150 MKT DE-30B 1
1 Delmag series of pile hammers is the most popular, with the D19-42 being the most widely used.

The contractor is responsible for determining the driving system required to successfully drive the pile to the minimum tip elevation and to reach the minimum nominal axial compressive resistance specified on the plans. The contractor is required to perform a drivability analysis to select an appropriate hammer size to ensure the pile can be driven without overstressing the pile and to prevent refusal of the pile prior to reaching the minimum tip elevation. The contractor shall plan pile driving activities and submit hammer energy requirements to the engineer for approval before driving. There is an exception to the contractor’s responsibility for the drivability analysis when WEAP is specified as the driving criteria for friction pile. When WEAP is specified for friction pile an inspector’s chart will be provided for the contractor in the electronic deliverables. For more detailed guidance see SEG 25-001 New Policy for Friction Pile.

Practical refusal is defined at 20 blows/inch or 240 blows per foot.

Driving should be terminated immediately once 30 blows/inch is encountered.

Nominal Driving Stress LRFD 10.7.8
Nominal driving stress ≤ 0.9*ϕda*Fy
For structural steel HP pile, Maximum nominal driving stress = 45 ksi
For CIP pile, Maximum nominal driving resistance, see EPG 751.36.5.7.1.2 or EPG 751.36.5.7.2.2 (unfilled pipe for axial analysis).

If analysis indicates the piles do not have sufficient structural or geotechnical strength or drivability issues exist, then consider increasing the number of piles.

751.36.5.12 Information to be Included on the Plans

See EPG 751.50 A1 Design Specifications, Loadings & Unit Stresses for appropriate design stresses to be included in the general notes.

See EPG 751.50 E2 Foundation Data Table for appropriate data to be included in the foundation data table for HP pile and CIP pile and any additional notes required below the table. See Bridge Standard Drawings “Pile” for CIP data table.







E2. Foundation Data Table

The following table is to be placed on the design plans and filled out as indicated.

(E2.1) [MS Cell] (E2.1) (Example: Use the underlined parts in the bent headings for bridges having detached wing walls at end bents only.)

Foundation Data1
Type Design Data Bent Number
1 (Detached
Wing Walls
Only)		 1 (Except
Detached
Wing Walls)		 2 3 4
Load
Bearing
Pile		 CECIP/OECIP/HP Pile Type and Size CECIP 14" CECIP 14" CECIP 16" OECIP 24" HP 12x53
Number
6 8 15 12 6
Approximate Length Per Each
50 50 60 40 53
Pile Point Reinforcement
 All All - All All
Min. Galvanized Penetration (Elev.)
303 2954 273 Full Length 300
Est. Max. Scour Depth 1002 (Elev.)
- - 285 - -
Minimum Tip Penetration (Elev.)
285 303 270 - -
Criteria for Min. Tip Penetration Min. Embed. Min. Embed. Scour - -
Pile Driving Verification Method DT DT DT DT DF
Resistance Factor 0.65 0.65 0.65 0.65 0.4
Design Bearing3 Minimum Nominal Axial
Compressive Resistance
175 200 300 600 250
Spread
Footing		 Foundation Material - - Weak Rock Rock -
Design Bearing Minimum Nominal
Bearing Resistance
- - 10.2 22.6 -
Rock
Socket		 Number
- - 2 3 -
Foundation Material - - Rock Rock -
Elevation Range
- - 410-403 410-398 -
Design Side Friction
Minimum Nominal Axial
Compressive Resistance
(Side Resistance)
- - 20.0 20.0 -
Foundation Material - - Weak Rock - -
Elevation Range
- - 403-385 - -
Design Side Friction
Minimum Nominal Axial
Compressive Resistance
(Side Resistance)
- - 9.0 - -
Design End Bearing
Minimum Nominal Axial
Compressive Resistance
(Tip Resistance)
- - 12 216 -
1 Show only required CECIP/OECIP/HP pile data for specific project.
2 Show maximum of total scour depths estimated for multiple return periods in years from Preliminary design which should be given on the Design Layout. Show the controlling return period (e.g. 100, 200, 500). If return periods are different for different bents, add a new line.
3 For LFD: For bridges in Seismic Performance Categories B, C and D, the design bearing values for load bearing piles given in the table should be the larger of the following two values:
  1. Design bearing value for AASHTO group loads I thru VI.
  2. Design bearing for seismic loads / 2.0
4 It is possible that min. tip penetration (elev.) can be higher than min. galvanized penetration (elev.).
Additional notes:
On the plans, report the following definition(s) just below the foundation data table for the specific method(s) used:

DT = Dynamic Testing
DF = FHWA-modified Gates Dynamic Pile Formula
WEAP = Wave Equation Analysis of Piles
SLT = Static Load Test

On the plans, report the following definition(s) just below the foundation data table for CIP Pile:
CECIP = Closed Ended Cast-In-Place concrete pile
OECIP = Open Ended Cast-In-Place concrete pile

On the plans, report the following equation(s) just below the foundation data table for the specific foundation(s) used:
Rock Socket (Drilled Shafts):
Minimum Nominal Axial Compressive Resistance (Side Resistance + Tip Resistance) = Maximum Factored Loads/Resistance Factors
Spread Footings:
Minimum Nominal Bearing Resistance = Maximum Factored Loads/Resistance Factor
Load Bearing Pile:
Minimum Nominal Axial Compressive Resistance = Maximum Factored Loads/Resistance Factor


Guidance for Using the Foundation Data Table:
Pile Driving Verification Method DF = FHWA-Modified Gates Dynamic Pile Formula
DT = Dynamic Testing
WEAP = Wave Equation Analysis of Piles
SLT = Static Load Test
Criteria for Minimum Tip Penetration Scour
Tension or uplift resistance
Lateral stability
Penetration anticipated soft geotechnical layers
Minimize post construction settlement
Minimum embedment into natural ground
Other Reason
Elevation reporting accuracy: Report to nearest foot for min. tip penetration, pile cleanout penetration, max. galvanized depth and est. max. scour depth. (Any more accuracy is acceptable but not warranted.)
For LFD Design
Use "Design Bearing" for load bearing pile and spread footing and use "Design Side Friction + Design End Bearing" for rock socket (drilled shaft).
For LRFD Design
Use "Minimum Nominal Axial Compressive Resistance" for load bearing pile, "Minimum Nominal Bearing Resistance" for spread footing and "Minimum Nominal Axial Compressive Resistance (Side Resistance + Tip Resistance)" for rock socket (drilled shaft).

Shallow Footings

(E2.10) (Use when shallow footings are specified on the Design Layout.)

In no case shall footings of Bents No.       and       be placed higher than elevations shown       and       , respectively.

Driven Piles

(E2.20) (Use when prebore is required and the natural ground line is not erratic.)

Prebore for piles at Bent(s) No.       and       to elevation(s)       and       , respectively.

(E2.21) (Use when prebore is required and the natural ground line is erratic.)

Prebore to natural ground line.

(E2.22) (Use when estimated maximum scour depth (elevation) for CIP piles is required.)

Estimated Maximum Scour Depth (Elevation) shown is for verifying Minimum Nominal Axial Compressive Resistance Design Bearing using dynamic testing only where pile resistance contribution above this elevation shall not be considered.

(E2.23) (Use when static test piles are required.) The number of piles in table should not include probe piles. If probe piles are specified, place an * beside the number of piles at the bents indicated.

 *One concrete probe pile shall be driven in permanent position, one for each bent, at Bents No.       and       .

(E2.24)

All piles shall be galvanized down to the minimum galvanized penetration (elevation).

(E2.25) (Use for all HP pile and when pile point reinforcement is required for CIP pile.)

Pile point reinforcement need not be galvanized. Shop drawings will not be required for pile point reinforcement.

(E2.26) (Use for LFD piling design when Design Bearing is determined from service loads and shown on the plans. See guidance on [MS Cell] (E2.1) for specific pile driving verification method. Example: Considered only for widenings, repairs and rehabilitations.)

All piling shall be driven to a minimum nominal axial compressive resistance equal to 3.5 2.75 2.25 2.00 times the Design Bearing as shown on the plans.

(E2.27) Use for galvanized piles.

The contractor shall make every effort to achieve the minimum galvanized penetration (elevation) shown on the plans for all piles. Deviations in penetration less than 5 feet of the minimum will be considered acceptable provided the contractor makes the necessary corrections to ensure the minimum penetration is achieved on subsequent piles.

(E2.28) Use when WEAP is specified as the pile driving criteria for friction pile. Place an * behind each instance of WEAP in the Foundation Data table. The pay item Pile Wave Analysis shall not be included when this note is used.

*See electronic deliverables file for pile driving inspector’s chart(s). MoDOT will provide alternate charts for different driving systems as needed per request. With the request, the contractor shall provide the hammer manufacturer make and model, and any modifications to the manufacturer’s recommended settings including hammer cushion information. The contractor shall provide the request 30 calendar days before pile driving operations begin.

REVISION REQUEST 4151

127.2.3.3.1 Missouri Unmarked Human Burials Law

If human skeletal remains are encountered during construction, their treatment will be handled in accordance with Sections 194.400 to 194.410, RSMo, as amended. When human remains are encountered, the Contractor shall first stop all work within a 330-ft. or 100-meter radius of the remains, and secondly, shall notify the MoDOT Construction Inspector and/or Resident Engineer who will contact the Historic Preservation section. Historic Preservation staff will in turn notify the local law enforcement (to ensure that it is not a crime scene) and the State Historic Preservation Office (SHPO) as per RSMo 194 or to notify SHPO what has occurred and that it is covered by Missouri’s Cemeteries Law, §§ 214. RSMo. If the contractor is unable to contact appropriate MoDOT staff, the contractor shall initiate the involvement by local law enforcement and the SHPO. A description of the contractor’s actions will be promptly made to MoDOT.

If the human remains are prehistoric, the agency must consult with Indian tribes who have with ancestral, historic, and ceded land connections to the area in which the remains are located to determine the appropriate treatment of the remains. Tribal consultation may result in the conclusion that the remains should be preserved in place and construction plans changed to facilitate their preservation.





127.2.9 Construction Inspection Guidance

Mitigation by data recovery is usually completed prior to construction if the presence of cultural resources is known. If artifacts are discovered during construction activities, the Historic Preservation section must be immediately notified. This will allow an inspection of the site by MoDOT HP staff to determine if further investigation is necessary before construction activities continue.

Sec. 107.8.2 and Sec. 203.4.8 of the Missouri Standard Specifications for Highway Construction require the contractor to take steps to preserve any such artifacts that may be encountered and to notify the MoDOT Construction Inspector or Resident Engineer of their presence. If it is necessary to discontinue operations in a particular area to preserve such objects, this section of the specifications is basis for a work suspension. In order to ensure compliance with applicable state laws, the MoDOT Construction Inspector or Resident Engineer cannot release remains or artifacts or allow the contractor to disturb the area within the 330-foot or 100-meter buffer space around these discovered items, until after consultation with MoDOT HP staff and until after all applicable requirements from FHWA or SHPO have been addressed.

127.2.9.1 Cultural Resources Encountered During Construction

If cultural resources are encountered during construction, the contractor shall immediately stop all work within a 330-foot or 100-meter buffer around the limits of the resource and shall not resume without specific authorization from a MoDOT Historic Preservation Specialist. The contractor shall notify the MoDOT Resident Engineer or Construction Inspector, who shall contact the MoDOT HP within 24 hours of the discovery. MoDOT HP shall contact FHWA and SHPO within 48 hours of learning of the discovery and provide an evaluation of the resource and reasonable efforts to see if it can be avoided. FHWA shall make an eligibility and effects determination based upon the preliminary evaluation and consul with MoDOT, and SHPO a minimize or mitigate any adverse effect. FHWA will notify the Council and any tribes that might attach religious and/or cultural significance to the property within 48 hours of this determination. FHWA shall take into account Council and Tribal recommendations regarding the eligibility of the property and proposed actions, and direct MoDOT to carry out the appropriate actions. MoDOT will provide FHWA and SHPO with a report of the actions when they are completed. FHWA shall provide this report to the council and the tribes.

127.2.9.2 Human Remains Encountered During Construction

If human remains are encountered during construction, the contractor shall immediately stop all work within a 330-foot or 100-meter radius of the remains and shall not resume without specific authorization from MoDOT HP Staff, and either the SHPO or the local law enforcement officer, whichever party has jurisdiction over and responsibility for such remains. The contractor shall notify the MoDOT Construction Inspector and/or Resident Engineer who will contact the MoDOT HP section within 24 hours of the discovery. MoDOT HP staff will immediately notify the local law enforcement (to ensure that it is not a crime scene) and the SHPO as per RSMo 194 or to notify SHPO what has occurred and that it is covered by Missouri’s Cemeteries Law, §§ 214. RSMo. MoDOT HP staff will notify FHWA that human remains have been encountered within 24 hours of being notified of the find. If, within 24 hours, the contractor is unable to contact appropriate MoDOT staff, the contractor shall initiate the involvement by local law enforcement and the SHPO. A description of the contractor’s actions will be promptly made to MoDOT. FHWA will notify any Indian tribe that might attach cultural affiliation to the identified remains as soon as possible after their identification. FHWA shall take into account Tribal recommendations regarding treatment of the remains and proposed actions, and then direct MoDOT HP to carry-out the appropriate actions in consultation with the SHPO. MoDOT shall monitor the handling of any such human remains and associated funerary objected, sacred object or objects of cultural patrimony in accordance with the Missouri Unmarked Human Burial Sites Act, §§ 194.400 – 194.410, RSMo.

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