Difference between revisions of "751.12 Barriers, Railings, Curbs and Fences"

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m (→‎751.12.2.9 Details of Mounting Light Poles on Safety Barrier Curbs: Per Bridge, updated spec to ASTM A449 and increased length of exposed thread in sec b-b figure)
(→‎751.12.4 Chain Link Fence: updated per RR3887)
 
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== 751.12.1 Standard Safety Barrier Bridge Curbs ==
+
To be found eligible for Federal-aid funding, new roadside safety devices should meet the crash test and evaluation criteria contained in the American Association of State Highway and Transportation Officials’ (AASHTO) Manual for Assessing Safety Hardware (MASH). Since neither FHWA nor AASHTO has a system in place to approve roadside devices, the responsibility is left with the States. In response, MoDOT has developed a MASH Implementation process. All roadside devices that are submitted after November 1, 2019, will be reviewed by the MASH Team for approval to use on Missouri roadways. Prior to November 1, 2019 roadside devices were considered using the criterion set forth in NCHRP Report 350 “Recommended Procedures for the Safety Performance Evaluation of Highway Features”.  While MASH requirements are only applicable to the NHS, the following guidelines are recommended for all bridges.
 
+
{|style="padding: 0.3em; margin-left:15px; border:2px solid #a9a9a9; text-align:left; font-size: 95%; background:#f5f5f5" width="300px" align="right"  
 
 
=== 751.12.1.1 Standard Safety Barrier Curbs used in Missouri ===
 
 
 
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
 
|-
 
|colspan="2"|[[Image:751.12 barrier curb - NJ Shape.gif]]
 
|-
 
|Type A<br/>Test Level TL-4
 
|Type B<br/>Test Level TL-4
 
|-
 
!colspan="2"|NJ Shape
 
|-
 
|colspan="2"| &nbsp;
 
|-
 
|colspan="2"|[[Image:751.12 barrier curb - type c & d.gif]]
 
|-
 
|Type C<br/>Test Level TL-5
 
|Type D<br/>Test Level TL-5
 
|}
 
 
 
 
 
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:left"
 
|-
 
!Note:
 
|For Type F (Temporary Barrier Curb), refer to Missouri Standard Plans 617.20.
 
|-
 
| &nbsp;
 
|For Thrie Beam Rails, see Widening & Repair information.
 
 
|-
 
|-
| &nbsp;
+
|See [https://www.modot.org/media/30418 SEG 21-01], Anchoring Barriers Over Precast Panels.
|See Structural Project Manager before using Type C or D barriers.
 
 
|}
 
|}
 +
AASHTO LRFD uses the term “railing” to refer to all types of bridge traffic barrier systems used on bridges. MoDOT uses the term “barrier” for solid concrete bridge railing (single-faced on the edge of roadway and dual-faced medians) and the term “railing” for barrier systems consisting of a rail(s) and supports.
  
== 751.12.2 Safety Barrier Bridge Curbs (NJ Shape) ==
+
==751.12.1 Concrete Barriers==
 
 
 
 
=== 751.12.2.1 General Design ===
 
 
 
New safety barrier curbs "shall be shown to be structurally and geometrically crashworthy".  Therefore, the shape of the safety barrier curb is selected based on crash-tested, or equivalent crash-tested geometry. 
 
 
 
The safety barrier curb used on new bridges shall be the 16” New Jersey (MO) safety shape barrier curb which has been crash-tested and FHWA approved as meeting test level TL-4.
 
  
Test level TL-4 shall be used for safety barrier curb designTL-4 is defined by AASHTO as being “generally acceptable for the majority of applications on high-speed highways, freeways, expressways, and interstate highways with a mixture of trucks and heavy vehicles”.
+
Type D barrier replaced Type B barrier (previously safety barrier curb) as the standard railing for bridges awarded after December 31, 2019. Similarly, Type C barrier replaced Type A barrier (previously median barrier curb).  Types H and G shall be used respectively for situations where Types D and C is considered impractical.
 +
[[image:751.12.1.jpg|center|600px]]
 +
Single sloped barriers have been shown to reduce vehicle climb and increase vehicle stability during redirections when compared to New Jersey shaped barriersSee the following sections for more details on standard barriers. Details for Type G have not been developed, but that does not prevent its use if need dictates.  
  
 +
Concrete barriers were approved for TL-3 or TL-4 test levels in accordance with the MASH 2016 standards.  The required MASH 2016 test level for bridges on the National Highway System (NHS) is TL-3, but the expectation is that the TL-4 requirement will be mandated in the next publication.
  
<center>[[Image:751.12 safety barrier curb dimensions.gif]]</center>
+
Test level TL-3 is defined by AASHTO as being “generally acceptable for a wide range of high-speed arterial highways with very low mixtures of heavy vehicles and with favorable site conditions.
<center>* Use Rustication on Highway Grade Seperations only</center>
 
<center>'''Safety Barrier Curb Dimensions'''</center>
 
  
 +
Test level TL-4 is defined by AASHTO as being “generally acceptable for the majority of applications on high-speed highways, freeways, expressways, and interstate highways with a mixture of trucks and heavy vehicles”.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
===751.12.1.1 Material Properties===
|+'''Material Properties'''
+
{| style="margin: 1em auto 1em auto"
!align="left"|Concrete
 
| &nbsp;
 
|-
 
|align="right"|Unit weight of reinforced concrete,
 
|<math>\, \gamma_c</math> = 150 <math>\,lb/ft^3</math>
 
|-
 
|align="right"|for modulus of elasticity,
 
|<math>\, \gamma_c</math> = 145 <math>\,lb/ft^3</math>
 
|-
 
!align="left"|Safety Barrier Curbs
 
| &nbsp;
 
|-
 
|align="left"|Safety Barrier Curbs shall consist of:
 
| &nbsp;
 
|-
 
|align="right"|Class B-1 Concrete
 
| <math>\, f'_c</math> = 4.0 ksi
 
|-
 
| &nbsp;
 
|<math>\, n</math> = 8
 
|-
 
!align="left"|Median Barrier Curbs
 
| &nbsp;
 
|-
 
|align="left"|Median Barrier Curbs shall consist of:
 
| &nbsp;
 
 
|-
 
|-
|align="right"|Class B-1 Concrete
+
!Class B-1 Concrete!! !! Epoxy Coated Reinforcing Steel
| <math>\, f'_c</math> = 4.0 ksi
 
 
|-
 
|-
| &nbsp;
+
|Unit weight (reinforced), wc = 0.150 kcf||width="15px| ||Yield strength, fy = 60.0 ksi
|<math>\, n</math> = 8
 
 
|-
 
|-
!align="left"|Reinforcing steel
+
|Compressive strength, f’c = 4.0 ksi|| ||Modulus of elasticity, Es = 29,000 ksi
| &nbsp;
 
 
|-
 
|-
|align="right"|Minimum yield strength,
+
|Modular ratio, n = 8|| ||
|<math>\, f_y</math> = 60.0 ksi
 
 
|-
 
|-
|align="right"|Steel modulus of elasticity
+
|Modulus of elasticity, Ec = 3644 ksi || ||
|<math>\, E_s</math> = 29000 ksi
 
 
|}
 
|}
  
=== 751.12.2.2 Standard Reinforcement Details ===
+
===751.12.1.2 General Details===
 +
Regardless of type of barrier shown the following sections are applicable for all concrete barrier types.
  
{|border="0" cellpadding="10" cellspacing="1" align="center" style="text-align:center"
+
Top of barrier shall be built parallel to grade with barrier joints (except at end bents) normal to grade.
  
|[[Image:751.12 r-bar no wearing surface.gif]]
+
All exposed edges of barrier shall have either a 1/2-inch radius or a 3/8-inch bevel, unless otherwise noted.  
|[[Image:751.12 r1-bar no wearing surface.gif]]
 
|[[Image:751.12 r2-bar no wearing surface.gif]]
 
|-
 
!rowspan="2" valign="top"|R-Bar<br/>Required for Slip Form Option
 
!R1-Bar<br/>Shape 19
 
!R2-Bar<br/>Shape 15
 
|-
 
!colspan="2"|R1 & R2-Bars permissible<br/>only when Slip Forming<br/>not allowed (*)
 
|-
 
|colspan="3"|[[Image:751.12 16in standard safety barrier curb no wearing surface.gif]]
 
|-
 
!colspan="3"|16" Safety Barrier Curb
 
|}
 
<blockquote>
 
(*) The single R bar adds to the rigidity of the reinforcement during construction and it is believed to help prevent cracking. The single bar also appears to assist maintaining uniform
 
reinforcement cover.
 
</blockquote>
 
  
 +
====751.12.1.2.1 Slip Forming====
 +
Conventional or slip forming may be used except for situations where slip forming is considered impractical.
  
 +
See barrier elevation sheets of the [http://www.modot.org/business/standard_drawings2/Barrier_curbs_new_title_block.htm barrier standard drawings] for the required details.
  
{|border="0" cellpadding="2" cellspacing="1" align="center" style="text-align:center"
+
Slip forming is impractical for prestressed double-tee bridges.
!colspan="4"|Reinforcement (No Wearing Surface)
 
|-
 
|rowspan="3"|[[Image:751.12 r-bar no wearing surface.gif]]
 
|rowspan="3"|[[Image:751.12 16in safety barrier curb no wearing surface.gif]]
 
|[[Image:751.12 r3-bar no wearing surface.gif]]
 
|[[Image:751.12 r4-bar no wearing surface.gif]]
 
|-
 
!#5-R3<br/>Shape 19
 
!#5-R4<br/>Shape 27 (*)
 
|-
 
|colspan="2"|[[Image:751.12 r-bar permissible shape no wearing surface.gif]]
 
|-
 
!valign="top"|R-Bar
 
!valign="top"|16" Safety Barrier Curb
 
!colspan="2"|R-Bar Permissible<br/>Alternate Shape (**)
 
|-
 
|colspan="4"| &nbsp;
 
|-
 
!colspan="4"|Reinforcement (1 3/4" Wearing Surface)
 
|-
 
|rowspan="3"|[[Image:751.12 r-bar 1.75 in wearing surface.gif]]
 
|rowspan="3"|[[Image:751.12 16in safety barrier curb 1.75 in wearing surface.gif]]
 
|[[Image:751.12 r3-bar 1.75 in wearing surface.gif]]
 
|[[Image:751.12 r4-bar 1.75 in wearing surface.gif]]
 
|-
 
!#5-R3<br/>Shape 19
 
!#5-R4<br/>Shape 27
 
|-
 
|colspan="2"|[[Image:751.12 r-bar permissible shape 1.75 in wearing surface.gif]]
 
|-
 
!valign="top"|R-Bar
 
!valign="top"|16" Safety Barrier Curb
 
!colspan="2"|R-Bar Permissible<br/>Alternate Shape (**)
 
|-
 
|colspan="4"| &nbsp;
 
|-
 
!colspan="4"|Reinforcement (2 1/4" Wearing Surface)
 
|-
 
|rowspan="3"|[[Image:751.12 r-bar 2.25 in wearing surface.gif]]
 
|rowspan="3"|[[Image:751.12 16in safety barrier curb 2.25 in wearing surface.gif]]
 
|[[Image:751.12 r3-bar 2.25 in wearing surface.gif]]
 
|[[Image:751.12 r4-bar 2.25 in wearing surface.gif]]
 
|-
 
!#5-R3<br/>Shape 19
 
!#5-R4<br/>Shape 27
 
|-
 
|colspan="2"|[[Image:751.12 r-bar permissible shape 2.25 in wearing surface.gif]]
 
|-
 
!valign="top"|R-Bar
 
!valign="top"|16" Safety Barrier Curb
 
!colspan="2"|R-Bar Permissible<br/>Alternate Shape (**)
 
|-
 
|colspan="4" align="left"|(*) Increase leg for latex or low slump concrete wearing surface.
 
|-
 
|colspan="4" align="left"|(**) The R3 bar and #5 bottom transverse slab bar in cantilever (P/S panels only) combination may be<br/>furnished as one bar as shown, at the contractor's option.
 
|}
 
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
 
|Note:
 
|align="left"|Use same grade reinforcing steel in Barrier Curb as in slab. Splice length for #5 bars in Barrier Curb = 35".
 
|-
 
| &nbsp;
 
|align="left"|Dimensions shown are also typical for structures with latex or low slump concrete (except as indicated).
 
|}
 
  
=== 751.12.2.3 End Bent Reinforcement ===
+
'''Cross Bracing C Bars'''
  
{|border="0" cellpadding="1" cellspacing="0" align="center" style="text-align:center"
+
Slip forming requires two No. 5 cross bracing C bars located each side of all joints and at barrier ends.
|+'''Non-Integral End Bents'''
 
|colspan="2"|[[Image:751.12 non-integral end bent end elevation of barrier curb.gif]]
 
|colspan="2"|[[Image:751.12 non-integral end bent elevation of barrier curb.gif]]
 
|-
 
!colspan="2"|End Elevation
 
!colspan="2"|Elevation of Barrier Curb
 
|-
 
|colspan="2"|[[Image:751.12 non-integral end bent section a-a.gif]]
 
|[[Image:751.12 non-integral end bent section b-b.gif]]
 
|[[Image:751.12 non-integral end bent section c-c.gif]]
 
|-
 
!colspan="2"|Section A-A
 
!Section B-B
 
!Section C-C
 
|-
 
|align="right"|*
 
|colspan="3" align="left"|Spaced with #5-K4 bars.
 
|-
 
|align="right"|**
 
|colspan="3" align="left"|Fit bar to follow transition face of curb.
 
|}
 
  
 +
List C bars in the Bill of Reinforcing Steel and note that bars are for the slip-formed option only.
  
{|border="0" cellpadding="1" cellspacing="0" align="center" style="text-align:center"
+
For barrier segments on top of the bridge deck, use 12-foot C1 bars.
|colspan="5"|All bars are epoxy coated.
 
|-
 
|colspan="5"|All bars are stirrup bends except for K4, K9, K10 & K11.
 
|-
 
|[[Image:751.12 non-integral end bent k1.gif]]
 
|[[Image:751.12 non-integral end bent k2.gif]]
 
|[[Image:751.12 non-integral end bent k3.gif]]
 
|[[Image:751.12 non-integral end bent k4.gif]]
 
|[[Image:751.12 non-integral end bent k5.gif]]
 
|-
 
!#5-K1<br/>Shape 19
 
!#5-K2<br/>Shape 14
 
!#5-K3<br/>Shape 27
 
!#5-K4<br/>Shape 7
 
!#5-K5<br/>Shape 25
 
|-
 
|[[Image:751.12 non-integral end bent k6.gif]]
 
|[[Image:751.12 non-integral end bent k7.gif]]
 
|[[Image:751.12 non-integral end bent k8.gif]]
 
|colspan="2"|[[Image:751.12 non-integral end bent k9.gif]]
 
|-
 
!#5-K6<br/>Shape 25
 
!#5-K7<br/>Shape 25
 
!#5-K8<br/>Shape 25
 
!colspan="2"|#5-K9<br/>Shape 20
 
|-
 
|colspan="2"|[[Image:751.12 non-integral end bent k10.gif]]
 
|colspan="2"|[[Image:751.12 non-integral end bent k11.gif]]
 
|rowspan="2" align="left"|(*) Increase leg for slab<br/>thickness greater than<br/>8 1/2".
 
|-
 
!colspan="2"|#4-K10<br/>Shape 20
 
!colspan="2"|#5-K11<br/>Shape 8
 
|}
 
 
 
  
 +
For barrier segments on top of the end bent wings (Type B, D or H):
 +
:For segment lengths less than 14'-4", use C2 bars with the following lengths:
  
<div id="integral end bent barrier curb"></div>
+
::{| border="1" class="wikitable" style="margin: 1em auto 1em auto" style="text-align:center"
{|border="0" cellpadding="1" cellspacing="0" align="center" style="text-align:center"
+
|+  
|+'''Integral End Bents'''
+
! style="background:#BEBEBE" rowspan="2"| !! colspan="6" |Barrier Segment Length
|colspan="2"|[[Image:751.12 integral end bent end elevation of barrier curb.gif]]
 
|colspan="2"|[[Image:751.12 integral end bent elevation of barrier curb.gif]]
 
|-
 
!colspan="2"|End Elevation
 
!colspan="2"|Elevation of Barrier Curb
 
|-
 
|colspan="2"|[[Image:751.12 integral end bent section a-a.gif]]
 
|[[Image:751.12 integral end bent section b-b.gif]]
 
|[[Image:751.12 integral end bent section c-c.gif]]
 
|-
 
!colspan="2"|Section A-A
 
!Section B-B
 
!Section C-C
 
|-
 
|align="right"|*
 
|colspan="3" align="left"|Spaced with #5-K4 bars.
 
 
|-
 
|-
|align="right"|**
+
!8' to < 9'!! 9' to < 10'!! 10' to < 11'!! 11' to < 12'!! 12' to < 13'!! 13' to <14'-4"
|colspan="3" align="left"|Fit bar to follow transition face of curb.
 
 
|-
 
|-
|align="right" valign="top"|***
+
|'''Bar Length''' ||5'-9" ||6'-9" ||7'-9" ||8'-9" ||9'-9" ||10'-6"
|colspan="3" align="left"|On skewed structures, if end K3 bar does not meet the Min. 1 1/2" clearance<br/>from front face of diaphragm, a K12 bar may be substituted.
 
 
|}
 
|}
  
 +
:For segment lengths 14'-4" to 18 feet, use 12-foot C1 bars.
 +
:For section greater than 18 feet, use two sets of 8-foot C2 bars.
  
{|border="0" cellpadding="1" cellspacing="2" align="center" style="text-align:center"
+
'''Textured Fiberglass Bars'''
|colspan="5"|All bars are epoxy coated.
 
|-
 
|colspan="5"|All bars are stirrup bends except for K4, K9, K10 & K11.
 
|-
 
|[[Image:751.12 integral end bent k1.gif]]
 
|[[Image:751.12 integral end bent k2.gif]]
 
|[[Image:751.12 integral end bent k3.gif]]
 
|[[Image:751.12 integral end bent k4.gif]]
 
|[[Image:751.12 integral end bent k5.gif]]
 
|-
 
!#5-K1<br/>Shape 19
 
!#5-K2<br/>Shape 14
 
!#5-K3<br/>Shape 27
 
!#5-K4<br/>Shape 7
 
!#5-K5<br/>Shape 25
 
|-
 
|[[Image:751.12 integral end bent k6.gif]]
 
|[[Image:751.12 integral end bent k7.gif]]
 
|[[Image:751.12 integral end bent k8.gif]]
 
|colspan="2"|[[Image:751.12 integral end bent k9.gif]]
 
|-
 
!#5-K6<br/>Shape 25
 
!#5-K7<br/>Shape 25
 
!#5-K8<br/>Shape 25
 
!colspan="2"|#5-K9<br/>Shape 20
 
|-
 
|colspan="2"|[[Image:751.12 integral end bent k10.gif]]
 
|colspan="2"|[[Image:751.12 integral end bent k11.gif]]
 
|[[Image:751.12 integral end bent k12.gif]]
 
|-
 
!colspan="2"|#4-K10<br/>Shape 20
 
!colspan="2"|#5-K11<br/>Shape 8
 
!#5-K12<br/>Shape 27
 
|}
 
  
 +
Slip forming requires three four-feet long No. 4 textured fiberglass bars centered at each joint.
  
 +
====751.12.1.2.2 Joints====
 +
See barrier elevation sheets of the [http://www.modot.org/business/standard_drawings2/Barrier_curbs_new_title_block.htm barrier standard drawings] for the required details.
  
 +
One-fourth-inch joints are located in the barrier at locations of negative moments to prevent cracking in the barrier. Barrier joints may be formed using ¼-inch joint filler in accordance with Sec 1057 or saw cut and seal with silicone joint sealant in accordance with Sec 717. Saw cuts joints may be used with the conventional forming option.
  
<div id="barrier curb details-semi deep"></div>
+
Joints are required when decks are continuous over intermediate bents for both continuous and simple span structures. These joints are also required at the front face of integral end bents. For placement of barrier joints at integral end bents see integral end bent details.
{|border="0" cellpadding="1" cellspacing="0" align="center" style="text-align:center"
+
[[image:751.12.1.2.2.1.jpg|center|550px]]  
|+'''Semi-Deep Abutments'''
 
|colspan="4"|[[Image:751.12 semi-deep abutment elevation of barrier curb.gif]]
 
|-
 
!colspan="4"|Elevation of Barrier Curb
 
|-
 
|width="35%"|[[Image:751.12 semi-deep abutment end elevation of barrier curb.gif]]
 
|width="35%"|[[Image:751.12 semi-deep abutment section a-a.gif]]
 
|colspan="2"|[[Image:751.12 semi-deep abutment section b-b.gif]]
 
|-
 
!End Elevation
 
!Section A-A
 
!colspan="2"|Section B-B
 
|-
 
  
|rowspan="2"|[[Image:751.12 semi-deep abutment section c-c.gif]]
+
Additional joints at 12-foot spacing from joint at intermediate bents may be required based on span lengths. The following details provide guidance on locating flexural joints near intermediate bents. This spacing will allow the full yield-line failure pattern to develop for Type D barrier. For simplicity, the 12-foot spacing shall also be used for all other concrete barrier types.
|rowspan="2"|[[Image:751.12 semi-deep abutment section d-d.gif]]
+
[[image:751.12.1.2.2.2.jpg|center|600px]]
|align="right" width="5%"|*
 
|colspan="4" align="left" |Spaced with #5-K4 bars.
 
|-
 
|align="right" |**
 
|colspan="4" align="left" |Fit bar to follow transition face of curb.
 
|-
 
!Section C-C
 
!Section D-D
 
| &nbsp;
 
| &nbsp;
 
|}
 
  
 +
====751.12.1.2.3 Plastic Waterstops====
 +
See barrier elevation sheets of the [http://www.modot.org/business/standard_drawings2/Barrier_curbs_new_title_block.htm barrier standard drawings] for the required details.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
Plastic waterstops are typically located inside formed joints to eliminate water seepage problems on grade separations. They shall be excluded over railroads and county roads and are only required on the lower side of superelevated decks.
|colspan="5"|All bars are epoxy coated.
 
|-
 
|colspan="5"|All bars are stirrup bends except for K4, K9, K10 & K11.
 
|-
 
|[[Image:751.12 semi-deep abutment k1.gif]]
 
|[[Image:751.12 semi-deep abutment k2.gif]]
 
|[[Image:751.12 semi-deep abutment k3.gif]]
 
|[[Image:751.12 semi-deep abutment k4.gif]]
 
|[[Image:751.12 semi-deep abutment k5.gif]]
 
|-
 
!#5-K1<br/>Shape 19
 
!#5-K2<br/>Shape 14
 
!#5-K3<br/>Shape 27
 
!#5-K4<br/>Shape 7
 
!#5-K5<br/>Shape 25
 
|-
 
|[[Image:751.12 semi-deep abutment k6.gif]]
 
|[[Image:751.12 semi-deep abutment k7.gif]]
 
|[[Image:751.12 semi-deep abutment k8.gif]]
 
|colspan="2"|[[Image:751.12 semi-deep abutment k9.gif]]
 
|-
 
!#5-K6<br/>Shape 25
 
!#5-K7<br/>Shape 25
 
!#5-K8<br/>Shape 25
 
!colspan="2"|#5-K9<br/>Shape 20
 
|-
 
|colspan="2"|[[Image:751.12 semi-deep abutment k10.gif]]
 
|colspan="2"|[[Image:751.12 semi-deep abutment k11.gif]]
 
|[[Image:751.12 semi-deep abutment k12.gif]]
 
|-
 
!colspan="2"|#4-K10<br/>Shape 20
 
!colspan="2"|#5-K11<br/>Shape 8
 
!#5-K12<br/>Shape 27
 
|}
 
  
 +
====751.12.1.2.4 Guardrail Attachment====
 +
See barrier at end bents sheets of the [http://www.modot.org/business/standard_drawings2/Barrier_curbs_new_title_block.htm barrier standard drawings] for the required details.
 +
[[image:751.12.2.6.jpg|center|325px]]
  
 +
====751.12.1.2.5 Superelevation====
 +
Superelevated slope, S.E., is in decimal format for the follow calculation, i.e. use 0.04 for 4.0%.
 +
[[image:751.12.2.5.1.jpg|center|650px]]
 +
[[image:751.12.2.5.2.jpg|center|670px]]
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
====751.12.1.2.6 Detached Wing Walls====
|+'''Continuous Concrete Slab'''
+
If the detached wing wall has more than one section, see the Structural Project Manager for possible additional joints in the barrier (between sections).  
|colspan="2"|[[Image:751.12 cont conc slab end bent end elevation of barrier curb.gif]]
 
|colspan="2"|[[Image:751.12 cont conc slab end bent elevation of barrier curb.gif]]
 
|-
 
!colspan="2"|End Elevation
 
!colspan="2"|Elevation of Barrier Curb
 
|-
 
|colspan="2"|[[Image:751.12 cont conc slab end bent section a-a.gif]]
 
|[[Image:751.12 cont conc slab end bent section b-b.gif]]
 
|[[Image:751.12 cont conc slab end bent section c-c.gif]]
 
|-
 
!colspan="2"|Section A-A
 
!Section B-B
 
!Section C-C
 
|-
 
|align="right"|*
 
|colspan="3" align="left"|Spaced with #5-K4 bars.
 
|-
 
|align="right"|**
 
|colspan="3" align="left"|Fit bar to follow transition face of curb.
 
|}
 
  
 +
The following details are for illustration purposes only:
 +
[[image:751.12.2.6 end bents.jpg|center|550px]]
  
{|border="0" cellpadding="1" cellspacing="2" align="center" style="text-align:center"
+
====751.12.1.2.7 Details of Mounting Light Poles on Safety Barrier Curbs====
|colspan="5"|All bars are epoxy coated.
+
[[image:751.12.1.2.7_01_11-13-23.jpg|center|550px]]
|-
+
[[image:751.12.1.2.7_02_11-13-23.jpg|center|625px]]
|colspan="5"|All bars are stirrup bends except for K4, K9, K10 & K11.
 
|-
 
|[[Image:751.12 cont conc slab end bent k1.gif]]
 
|[[Image:751.12 cont conc slab end bent k2.gif]]
 
|[[Image:751.12 cont conc slab end bent k3.gif]]
 
|[[Image:751.12 cont conc slab end bent k4.gif]]
 
|[[Image:751.12 cont conc slab end bent k5.gif]]
 
|-
 
!#5-K1<br/>Shape 19
 
!#5-K2<br/>Shape 14
 
!#5-K3<br/>Shape 27
 
!#5-K4<br/>Shape 7
 
!#5-K5<br/>Shape 27
 
|-
 
|[[Image:751.12 cont conc slab end bent k6.gif]]
 
|[[Image:751.12 cont conc slab end bent k7.gif]]
 
|[[Image:751.12 cont conc slab end bent k8.gif]]
 
|colspan="2"|[[Image:751.12 cont conc slab end bent k9.gif]]
 
|-
 
!#5-K6<br/>Shape 27
 
!#5-K7<br/>Shape 27
 
!#5-K8<br/>Shape 27
 
!colspan="2"|#5-K9<br/>Shape 20
 
|-
 
|colspan="2"|[[Image:751.12 cont conc slab end bent k10.gif]]
 
|colspan="2"|[[Image:751.12 cont conc slab end bent k11.gif]]
 
|&nbsp;
 
|-
 
!colspan="2"|#4-K10<br/>Shape 20
 
!colspan="2"|#5-K11<br/>Shape 8
 
|&nbsp;
 
|-
 
|align="right" valign="top"|*
 
|colspan="4" align="left" valign="top"|According to the development length allowed with the slab depth used, bar may or may not be hooked.  Development length starts at slab/barrier interface, basic development length for a straight, #5 epoxy coated bar is 18".
 
|-
 
|align="right" valign="top"|**
 
|colspan="4" align="left" valign="top"|Length varies depending on slab depth.  Extend bar to within 1" of construction joint at bottom of slab.
 
|-
 
|align="right" valign="top"|***
 
|colspan="4" align="left" valign="top"|Use Shape 11 or create shape as necessary when development length requires hook.
 
|}
 
  
=== 751.12.2.4 Slip-Form Reinforcement Details ===
+
Anchor bolts and nuts shall be in accordance with ASTM F1554 Grade 55. Anchor bolts, nuts and washers shall be fully galvanized, See [[751.50_Standard_Detailing_Notes#H4._Conduit_System|751.50.H4.2.2]] for additional information.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
'''Note to Detailer:''' Extend slab transverse steel to edge of slab in blister region often shown with an additional detail with the slab details.
  
|[[Image:751.12 section at end bent (optional slip-form barrier).gif]]
+
'''Note:''' Conduit not shown for clarity.
|-
 
!Section at End Bent (Optional Slip-Form Barrier)
 
|-
 
| &nbsp;
 
|-
 
|[[Image:751.12 section near joint (optional slip-form barrier).gif]]
 
|-
 
!Section Near Joints (Optional Slip-Form Barrier)
 
|-
 
| &nbsp;
 
|-
 
|[[Image:751.12 optional slip-form barrier section a-a.gif]]
 
|-
 
!Section A-A
 
|-
 
|(*) Each side of Joint Location.
 
|}
 
  
'''NOTE TO DETAILER:'''
+
===751.12.1.3 Type D and H (42ʺ and 32ʺ single sloped railing)===
 +
The 42-inch single sloped Type D barrier shall be used for railing on all new or replacement bridge projects except where sight distance is a concern.  Type D meets the height requirements for both MASH 2016 TL-4 (36ʺ) and Occupational Safety and Health Administration’s OSHA (42ʺ).  Type D barrier has been reviewed by the Midwest Roadside Safety Facility (MwRSF) and is compliant with MASH 2016 TL-4.  This assessment is applicable for continuous and discontinuous sections of the barrier.  Type D barrier shall be used on all redecks and rehabs where the full length of barrier is being replaced with exceptions as outlined in [[751.1 Preliminary Design#751.1.3.4 Barrier or Railing Type, Height and Guidelines for Curb Blockouts|EPG 751.1.3.4 Barrier or Railing Type, Height and Guidelines for Curb Blockouts]]. The Type D barrier dimensions shall not be adjusted for inclusion of a wearing surface.
  
Optional Slip-Form Safety Barrier Curb details shall be placed on all jobs (except Prestressed Double-Tee Structures) where applicable.
+
The 32-inch single sloped Type H barrier shall be used for railing, upon approval of the SPM or SLE, on all new or replacement bridge projects where sight distance concerns prohibit the use of Type D.  Type H has the same front face slope as Type DThe minimum height for MASH 2016 TL-3 is 30 inches so there are minimal concerns with Type H for future overlays. Type H barrier has been reviewed by the Midwest Roadside Safety Facility (MwRSF) and is compliant with MASH 2016 TL-3This assessment is applicable for continuous and discontinuous sections of the barrier.  When a wearing surface is applied with the newly constructed Type H barrier, a pedestal is recommended to keep the holes for the guardrail attachment in the same location with respect to the top of the barrier.
   
 
Add #5 cross bracing bars for Slip-Form optionBase the length of these bars on the shortest distance between joints throughout the structure. Show the C-Bars in the Bar List and note that these bars are for the Slip-Form option only.
 
  
=== 751.12.2.5 SBC for Wing with Detached Wing Wall ===
+
====751.12.1.3.1 Typical Section====
 +
All values may be used with both 2.0% and 3/16 inch-per-foot cross slopes.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
See [[#751.12.1.2.5 Superelevation|EPG 751.12.1.2.5 Superelevation]] for adjustment of values for different cross slopes.
 +
[[image:751.12.1.3.1.jpg|center|700px]]
  
|colspan="2"|[[Image:751.12 safety barrier curb on non-integral end bent.gif]]
+
====751.12.1.3.2 Typical Section Reinforcement====
|-
+
The single R bar adds to the rigidity of the reinforcement during construction and it is believed to help prevent cracking. The single bar also appears to assist maintaining uniform reinforcement cover.  
!colspan="2"|SBC on Non-Integral End Bent (*)
 
|-
 
| &nbsp;
 
|-
 
|colspan="2"|[[Image:751.12 safety barrier curb on integral end bent.gif]]
 
|-
 
!colspan="2"|SBC on Integral End Bent (*)
 
|-
 
|align="right"|(*)
 
|align="left"|Detached Wing Wall shown is for illustration purpose only.
 
|-
 
| &nbsp;
 
|align="left"|If the detached wing wall has more than one section, see the Structural Project Manager<br/>for possible additional joints in the safety barrier curb (between sections).
 
|}
 
  
=== 751.12.2.6 Guard Rail Attachment Detail ===
+
Splice length for horizontal #5 bars in barrier curb shall be 37 inches.  
  
 +
All bent bars are formed using stirrup bends except for the Type D #5-R1 bars.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
All values may be used with both 2.0% and 3/16 inch-per-foot cross slopes.
 +
[[image:751.12.1.3.2-001-2024.png|center]]
  
|[[Image:751.12 guard rail attachment detail part elevation a-a.gif]]
+
====751.12.1.3.3 End of Barrier Reinforcement====
|[[Image:751.12 guard rail attachment detail part elevation.gif]]
+
See [http://www.modot.org/business/standard_drawings2/Barrier_curbs_new_title_block.htm barrier standard drawings] for the required details.
|-
+
 
!Part Elevation A-A
+
All bent bars are formed using stirrup bends.
!Part Elevation
 
|-
 
|&nbsp;
 
|[[Image:751.12 guard rail attachment detail part plan.gif]]
 
|-
 
|&nbsp;
 
!Part Plan
 
|-
 
|colspan="2"|[[Image:751.12 guard rail attachment detail auxiliary view.gif]]
 
|-
 
!colspan="2"|Auxiliary View
 
|}
 
  
=== 751.12.2.7 Joint & Rustication Details ===
+
All dimensions shown may be used with both 2.0% and 3/16 inch-per-foot cross slopes.
  
'''Curb Expansion Joints.''' Openings required for expansion shall be provided in the barrier curb in conjunction with deck joints. For details of expansion joints in barrier curb see expansion device details.
+
=====751.12.1.3.3.1 Type D Ending on Integral End Bents=====
 +
Use when distance between upper and lower construction joint in wings is at least 28½ inches.
 +
[[image:751.12.1.3.3.1.1 2021.jpg|center|700px]]
 +
[[image:751.12.1.3.3.1-002-2024.png|center|700px]]
 +
[[image:751.12.1.3.3.1-003-2024.png|center|700px]]
 +
[[image:751.12.1.3.3.1-004-2024.png|center|700px]]
  
'''Curb Joints.'''  1/4 in. joints are located in the barrier curb at locations of negative moments to prevent cracking in the barrier curb. These joints are required when decks are continuous over intermediate bents for both continuous and simple span structures. These joints are also required at the front face of integral end bents. For details of 1/4 in. curb joints at integral end bents see integral end bent details.
+
=====751.12.1.3.3.2 Type H Ending on Integral End Bents=====
 +
Use when distance between upper and lower construction joint in wings is at least 28½ inches.
 +
[[image:751.12.1.3.3.2.1 2021.jpg|center|700px]]
 +
[[image:751.12.1.3.3.2-002-2024.png|center|700px]]
  
'''Rustication.''' Rustication shall be used on grade separations only. Rustication shall be terminated four feet from the end of the barrier curb.
+
=====751.12.1.3.3.3 Type D Ending on Shallow Integral End Bents=====
 +
Use when distance between upper and lower construction joint in wings is less than 28½ inches.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
Formulas extend bars to within 1½ʺ of lower construction joint.
  
!colspan="3"|Cast-In-Place Barrier Curbs
+
[[image:751.12.1.3.3.3.1 2021.jpg|center|700px]]
|-
+
[[image:751.12.1.3.3.3-002-2024.png|center|700px]]
|colspan="3"|[[Image:751.12 joint and rustication details plan of curb joints.gif]]
+
[[image:751.12.1.3.3.3-003-2024.png|center|700px]]
|-
+
[[image:751.12.1.3.3.3-004-2024.png|center|700px]]
| || || width=400px | &nbsp;&nbsp;&nbsp;Note: Sawcut between spans shall be offset from centerline of intermediate bent to match any existing offset.
 
|-
 
!align="right"|Continuous Structures Part Plan
 
||
 
!&nbsp;&nbsp;&nbsp;Continuous Re-Deck of Simple Span Structures Part Plan
 
|-
 
|colspan="3"| &nbsp;
 
|-
 
|colspan="3"|[[Image:751.12 joint and rustication details all types of cont structure elevation.gif]]
 
|-
 
!colspan="3"| Part Section Showing Placement of Joints
 
|}
 
{|cellspacing="1" align="center"
 
|align="right" valign="top"|*||One space = 1/4 Span to nearest 1 in. increment (Span < 40 ft.)
 
|-
 
| || One space = 10 ft. (Span = 40 ft. to 125 ft.)
 
|-
 
| || Two spaces = 10 ft. (Span > 125 ft.)
 
|}
 
  
 +
=====751.12.1.3.3.4 Type H Ending on Shallow Integral End Bents=====
 +
Use when distance between upper and lower construction joint in wings is less than 28½ inches.
  
 +
Formulas extend bars to within 1½ʺ of lower construction joint.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
[[image:751.12.1.3.3.4.1 2021.jpg|center|680px]]
 +
[[image:751.12.1.3.3.4-002-2024.png|center|700px]]
  
!colspan="2"|Optional Slip-Form Barrier Curbs
+
=====751.12.1.3.3.5 Type D Ending on Non-Integral End Bents=====
|-
+
Use when distance between upper and lower construction joint in wings is at least 28½ inches.
|colspan="2"|[[Image:751.12 joint and rustication details optional slip-form section thru joint and section a-a.gif]]
+
[[image:751.12.1.3.3.5-001-2024.png|center|700px]]
|-
+
[[image:751.12.1.3.3.5-002-2024.png|center|700px]]
!width="410pt"|Section A-A
+
[[image:751.12.1.3.3.5-003-2024.png|center|700px]]
!width="300pt"|Section Thru Joint
+
[[image:751.12.1.3.3.5-004-2024.png|center|700px]]
|-
 
|colspan="2"|[[Image:751.12 joint and rustication details optional slip-form all types of cont structure elevation.gif]]
 
|-
 
!colspan="2"|Part Section Showing Placement of Joints
 
|}
 
 
 
{|cellspacing="1" align="center"
 
|}
 
 
 
 
 
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
 
|-
 
|colspan="2"|[[Image:751.12 joint and rustication details optional slip-form part plan continuous structures.gif]]
 
|-
 
| || width="300px"|Note: Sawcut between spans shall be offset from centerline of intermediate bent to match any existing offset.
 
|-
 
!Continuous Structures Part Plan
 
!Continuous Re-Deck of Simple Span Structures Part Plan
 
|-
 
| || width="300px"|'''Note:''' Rustication shall be used on grade separations only. Terminate rustication 4 ft. 0 in. from end of wing.
 
|}
 
  
 +
=====751.12.1.3.3.6 Type H Ending on Non-Integral End Bents=====
 +
Use when distance between upper and lower construction joint in wings is at least 28½ inches.
 +
[[image:751.12.1.3.3.6-001-2024.png|center|700px]]
  
 +
=====751.12.1.3.3.7 Type D Ending at End of Slab (Redecks)=====
 +
Splice length of #5 K12 and #5 K13 bars with #5 R-bars shall be 37 inches.
 +
[[image:751.12.1.3.3.7-001-2024.png|center|700px]]
 +
[[image:751.12.1.3.3.7-002-2024.png|center|750px]]
 +
[[image:751.12.1.3.3.7-003-2024.png|center|700px]]
 +
[[image:751.12.1.3.3.7-004-2024.png|center|700px]]
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
=====751.12.1.3.3.8 Type H Ending at End of Slab (Redecks)=====
 +
Splice length of #5 K7 bars with #5 R-bars shall be 37 inches.
 +
[[image:751.12.1.3.3.8-001-2024.png|center|700px]]
 +
[[image:751.12.1.3.3.8-002-2024.png|center|700px]]
  
|[[Image:751.12 joint and rustication details part section showing rustication details.gif]]
+
===751.12.1.4 Type B (32ʺ New Jersey Shaped Railing)===
|align="left"|'''Note:''' Rustication to be used on<br/>highway grade separation only.<br/>End rustication 4'-0" from end<br/>of wing.
+
The 32-inch New Jersey shaped railing, previously referred to as safety barrier curb, shall not be used on new construction projects.  This includes redecks and rehabs where the full length of barrier is being replaced. Type B barrier may be replaced in kind where spot work is required (i.e., expansion joint replacements).  For wearing surface projects, where the grade is not being increased more than 2 inches, the existing Type B barrier may be used in place in accordance with [[751.1 Preliminary Design#751.1.3.4 Barrier or Railing Type, Height and Guidelines for Curb Blockouts|EPG 751.1.3.4]].
|-
 
!Part Section Showing Rustication Details
 
| &nbsp;
 
|}
 
  
=== 751.12.2.8 Plastic Waterstop ===
+
=====751.12.1.4.1 Typical Section=====
 +
[[image:751.12.1.4.1.jpg|center|650px]]
 +
See [[#751.12.1.2.5 Superelevation|EPG 751.12.1.2.5 Superelevation]] for adjustment of values for different cross slopes.
  
To eliminate water seepage problems, use a plastic waterstop, as specified, and in accordance with details shown below.
+
=====751.12.1.4.2 Typical Section Reinforcement=====
+
The single R bar adds to the rigidity of the reinforcement during construction and it is believed to help prevent cracking. The single bar also appears to assist maintaining uniform reinforcement cover.  
Use a plastic waterstop at all safety barrier curb joints on grade separations, except over railroads and county roads.
 
 
Use a plastic waterstop on lower safety barrier curb joint only, for structures with superelevation on grade separations.
 
  
 +
Splice length for horizontal #5 bars in barrier curb shall be 37 inches.
  
<center>[[Image:751.12 plastic waterstop on bridge filled joint detail.gif]]</center>
+
All bent bars are formed using stirrup bends except for the R1 bars.
<center>* Rustication to be used on highway grade separations only.</center>
+
[[image:751.12.1.4.2-001-2024.png|center]]
<center>'''Filled Joint Detail'''</center>
 
  
=== 751.12.2.9 Details of Mounting Light Poles on Safety Barrier Curbs ===
+
=====751.12.1.4.3 End of Barrier Reinforcement=====
 +
See barrier ending on end bents sheets of the [http://www.modot.org/business/standard_drawings2/Barrier_curbs_new_title_block.htm barrier standard drawings] for the required details. The bars shown below are for barrier ending on wing walls; see barrier ending at end of slab sheet of the barrier standard drawings for reinforcement details for barrier ending on slabs.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
Splice length of #5-K9 bars with #4 K-bars above wing walls shall be 31 inches (embedment of #5 bars controls over splice length of #4 bars).
  
|[[Image:751.12 details of mounting light poles-part plan1.gif|300px]]
+
All bent bars are formed using stirrup bends except for the K4 and K11 bars.  
|colspan="2"|[[Image:751.12 details of mounting light poles-part plan2.gif|325px]]
 
|-
 
!Part Plan
 
!colspan="2"|Part Plan
 
|-
 
|[[Image:751.12 details of mounting light poles-section a-a.gif|330px]]
 
|colspan="2"|[[Image:751.12 details of mounting light poles-section b-b 2010.gif|430px]]
 
|-
 
!Section A-A
 
!colspan="2"|Section B-B
 
|-
 
|[[Image:751.12 details of mounting light poles bar shape 30.gif]]
 
|[[Image:751.12 details of mounting light poles bar shape 13.gif]]
 
|[[Image:751.12 details of mounting light poles bar shape 10.gif]]
 
|-
 
|colspan="3" align="left"|Anchor bolts and nuts shall be in accordance with ASTM A449.  Anchor bolts, nuts and washers shall be fully galvanized.
 
|-
 
|colspan="3" align="left"|'''Note to Detailer:''' Extend slab transverse steel to edge of slab in blister region.
 
|-
 
|colspan="3" align="left"|'''Note:''' Conduit not shown for clarity.
 
|}
 
  
=== 751.12.2.10 Superelevation Details ===
+
'''Ending on Integral End Bents and Semi-Deep Abutments'''
 +
 +
Use when distance between upper and lower construction joint in wings is at least 28½ inches.
 +
[[image:751.12.1.4.3-001-2024.png|center|600px]]
 +
[[image:751.12.1.4.3-002-2024.png|center|750px]]
  
<center>[[Image:751.12 superelevation details-section thru superelevated slab.gif]]</center>
+
: <big>'''*'''</big> On skewed integral end bents, if the end K3 bars do not meet the minimum 1 1/2" clearance from the front face of the diaphragm, a K12 bar shall be substituted.
<center>'''Section Thru Superelevated Slab'''</center>
 
  
 +
: <big>'''*'''</big> Based on no wearing surface, adjust as needed. Example: Add 2ʺ for 2ʺ W.S.
  
<center>[[Image:751.12 superelevation details-section thru superelevated approach slab at integral end bent.gif]]</center>
+
: <big>'''*'''</big> Also based on 8½ʺ slab, adjust as needed. Example: Subtract 1ʺ for 7½ʺ slab
<center>'''Section Thru Superelevated Approach Slab at Integral End Bent'''</center>
 
  
  
<center>[[Image:751.12 superelevation details-section thru superelevated approach slab at non-integral end bent.gif]]</center>
+
'''Ending on Shallow Integral End Bents'''
<center>'''Section Thru Superelevated Approach Slab at Non-Integral End Bent'''</center>
 
  
{|align="center"
+
Use when distance between upper and lower construction joint in wings is less than 28½ inches.
 +
[[image:751.12.1.4.3.3 2021.jpg|center|600px]]
 +
[[image:751.12.1.4.3-004-2024.png|center|650px]]
  
|"A"|| = 2'-8" + (Superelev. Slope x 16")
+
'''Ending on Non-Integral End Bents '''
|-
 
|"B"|| = 2'-8" - (Superelev. Slope x 16")
 
|-
 
|"C"|| = 8 1/2" + (Superelev. Slope x 16")
 
|-
 
|"D"|| = 8 1/2" - (Superelev. Slope x 16")
 
|}
 
  
=== 751.12.2.11 Expansion Device Movement Gauge ===
+
Use when distance between upper and lower construction joint in wings is at least 28½ inches.
 +
[[image:751.12.1.4.3-005-2024.png|center|600px]]
 +
[[image:751.12.1.4.3-006-2024.png|center|650px]]
  
All expansion joints shall be equipped with a movement gauge so an historical visual record showing total movement can be established.
+
===751.12.1.5 Type C (42ʺ Single Sloped Median)===
 +
====751.12.1.5.1 Typical Section====
 +
[[image:751.12.1.5.1.jpg|center|275px]]
  
<center>[[Image:751.12 expansion device movement guage details-elevation view of movement guage.gif]]</center>
+
====751.12.1.5.2 Typical Section Reinforcement====
<center>'''Elevation View of Movement Gauge'''</center>
+
[[image:751.12.1.5.2-001-2024.png|center|650px]]
  
<center>[[Image:751.12 expansion device movement guage details-plan view of movement guage.gif]]</center>
+
===751.12.1.6 Type A (32ʺ New Jersey Shaped Median)===
<center>'''Plan View of Movement Gauge'''</center>
+
Note: Use same grade reinforcing steel in barrier as in slab.
 +
::: Splice length for #5-R bars in barrier  = 37".
 +
::: Do not use this barrier over precast prestressed panels.
 +
[[image:751.12.1.6-001-2024.png|center|475px]]
  
 +
'''Twin Bridge Median Barrier Details'''
 +
[[image:751.12.1.6.1 2021.jpg|center|375px]]
  
'''Add following notes to plans:'''
+
==751.12.2 Two Tube Rail (Top Mounted)==
  
Notes:
+
'''38-inch Two Tube Rail'''
  
A movement gauge shall be provided on one side of
+
Consult the Structural Project Manager prior to use due to cost.
bridge at all safety barrier curb expansion joints.
+
:* Meets TL-4 (MASH 2016)
+
:* May be used for decks not less than 6-1/2 inches.
All steel shall be galvanized.
+
:* Uses an 18-inch wide curb. If the abutment uses turned-back wings they must be 18-inches thick.
+
:* Acceptable for use when site distance is a concern.
Cost of movement gauge, complete-in-place, shall be
+
:* Requires the 38-inch Two Tube Rail Transition for the bridge approaches. See [https://www.modot.org/standard-plans-section-600 STD. Plan 606.61].
included in the contract unit price bid for Safety
 
Barrier Curb.
 
  
== 751.12.3 Medians ==
+
'''32-inch Two Tube Rail '''
  
 +
Consult the Structural Project Manager prior to use due to cost.
 +
:* Meets TL-4 (NCHRP 350)
 +
:* Typically used on redecks, widenings, and railing or full-length cantilever replacements where the 38-inch Two Tube Rail is not practical.
 +
:* May be used on adjacent box beam bridges where reinforcement is embedded in the beam.
 +
:* Acceptable for use when roadway width or site distance is a concern.
 +
:* See [[751.1 Preliminary Design#751.1.3.4 Barrier or Railing Type, Height and Guidelines for Curb Blockouts|EPG 751.1.3.4 Barrier or Railing Type, Height and Guidelines for Curb Blockouts]] for additional requirements for design speed and AADT.
 +
:* Curb is intrinsic to TL rating and shall be used. Curb shall be used to prevent drainage over deck.
 +
:* Requires a Bridge Anchor Section ([https://www.modot.org/missouri-standard-plans-highway-construction STD. Plan 606.22]) for bridge approaches minus the bearing and connector plates.
  
=== 751.12.3.1 Double Faced Median Barrier Curb (NJ Shape) ===
+
'''Details'''
  
{|
+
{| border="1" class="wikitable" style="margin: 1em auto 1em auto" style="text-align:center"
|valign="top"|Note:||Use same grade reinforcing steel in barrier curb as in slab.
+
|+
|-
+
| style="background:#BEBEBE" width="300" |'''[http://www.modot.org/business/consultant_resources/bridgestandards.htm Bridge Standard Drawings]'''
|&nbsp;||Splice length for #5-R bars in barrier curb = 35".
 
 
|-
 
|-
|&nbsp;||Do not use this barrier curb over precast prestressed panels.
+
|align="center"|[http://www.modot.org/business/standard_drawings2/TwoTubeRail.htm Two Tube Rail]
 
|}
 
|}
  
 +
</center>
  
{|
+
==751.12.3 Median Curbs==
|width="100pt" valign="top"|Note to detailer:||Provide slip-form option for double faced median safety barrier curb.  For slip-form option additional #5 cross bracing bars shall be placed on both sides of all joints  and R2 bars shall be one bar.
+
[[image:751.12.3.1.jpg|center|550px]]
|}
+
:::'''Note:''' All reinforcement shown shall be epoxy coated.  
  
 +
Details shown are very general. Consult Design Layout for specific details for each individual structure.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
[[image:751.12.3.2.jpg|center|700px]]
 +
[[image:751.12.3.3.jpg|center|650px]]
  
|[[Image:751.12 double-faced median barrier curb reinforcement-r2 bar.gif]]
+
==751.12.4 Chain Link Fence==
|[[Image:751.12 double-faced median barrier curb reinforcement-r4 bar.gif]]
+
'''Design Criteria: '''
|-
 
!R2 Bar<br/>Shape 15
 
!R4 Bar<br/>Shape 27
 
|-
 
|colspan="2"|[[Image:751.12 section thru double faced median barreir curb.gif]]
 
|-
 
!colspan="2"|Section Thru Double Faced Median Barrier Curb
 
|-
 
|colspan="2"| &nbsp;
 
|-
 
!colspan="2"|Twin Bridge Median Barrier Curb Details
 
|-
 
|colspan="2"|[[Image:751.12 section thru median curb with open joint.gif]]
 
|-
 
!colspan="2"|Section Thru Median with Open Joint
 
|}
 
  
=== 751.12.3.2 Concrete Median Curbs ===
+
Dead load of fence fabric weight: 10 pounds per linear foot.  
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
Wind load for chain link or metal fabric fence: GREATER OF 0.015 ksf acting normal to the entire surface per LRFD 13.8.2 OR 0.11 x entire surface x calculated wind pressure (11% is effective surface area per MoDOT practice).
  
|[[Image:751.12 concrete median curbs-open joint (twin bridges typ).gif]]
+
<center>
|-
+
{| class="wikitable" border="1" style="text-align:center"
!Open Joint (Twin Bridges Typ.)
+
|+
|-
+
| style="background:#BEBEBE" width="300" |'''[https://www.modot.org/bridge-standard-drawings Bridge Standard Drawings]'''
|[[Image:751.12 concrete median curbs-barrier class (no joint).gif]]
 
|-
 
!Barrier Class (No Joint)
 
|-
 
|[[Image:751.12 concrete median curbs-mountable class.gif]]
 
|-
 
!Mountable Class
 
|-
 
|'''Note:''' All reinforcement shown shall be epoxy coated.
 
 
|-
 
|-
|Details shown are very general.  Consult Design Layout for specific details for each individual structure.
+
| (Fences-FEN)
 
|}
 
|}
 +
</center>
  
 +
==751.12.5 Decorative Pedestrian Fence==
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
===751.12.5.1 Design===
|+'''Concrete Median Curbs (Permissable Alternates)'''
 
|colspan="2" align="left"|'''Bent Bar:'''
 
|-
 
|[[Image:751.12 concrete median curbs (permissalbe alternates)-open joint (twin bridges typ.).gif]]
 
|[[Image:751.12 concrete median curbs (permissalbe alternates)-barrier class (no joint).gif]]
 
|-
 
!Open Joint (Twin Bridges Typ.)
 
!Barrier Class (No Joint)
 
|-
 
|[[Image:751.12 concrete median curbs (permissalbe alternates)-detail a.gif]]
 
|[[Image:751.12 concrete median curbs (permissalbe alternates)-detail b.gif]]
 
|-
 
!Detail "A"
 
!Detail "B"
 
|-
 
|rowspan="2"|[[Image:751.12 concrete median curbs (permissalbe alternates)-field bent bar.gif]]
 
|align="left" valign="bottom"|Add note to plans:
 
|-
 
|align="left" valign="top"|No additional payment will be allowed for the usage of<br/>either alternate anchoring systems.
 
|-
 
|colspan="2" align="left"|'''Resin Anchor:'''
 
|-
 
|colspan="2"|[[Image:751.12 concrete median curbs (permissalbe alternates)-resin anchor choice.gif]]
 
|-
 
|colspan="2"|'''Note:''' All reinforcement shown shall be epoxy coated.
 
|}
 
  
== 751.12.4 Chain Link Fence ==
+
Decorative pedestrian fencing shall not be used without approval of the core team. Design of Decorative Pedestrian Fence is completed by consultant or contractor in accordance with LRFD 13.  [https://www.modot.org/bridge-pre-qualified-products-list Bridge Pre-Qualified Products List] contains a listing of decorative pedestrian fence manufacturers which have been approved for use.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
General Guidelines
 +
:*Decorative Pedestrian fences are limited to minimum 3’-6” height from top of deck or sidewalk and maximum of 8’-0” post height.
 +
:*Decorative Pedestrian fences are limited to maximum 8’-0” post to post spacing.
 +
:*The base plate footprint shall match that provided in the [https://www.modot.org/bridge-standard-drawings Bridge Standard Drawings].  A flat base plate is provided for decorative pedestrian fences located on Type H barriers and pedestrian curbs.  Bent base plates are required for installations on Type B and Type D barriers due to the limited footprint available.
  
|colspan="2"|[[Image:751.12 pedestrian overpass-superstructure near steps.gif]]
 
|-
 
!colspan="2"|Superstructure Near Steps
 
|-
 
!colspan="2"|&nbsp;
 
|-
 
|colspan="2"|[[Image:751.12 pedestrian overpass-superstructure at or near end panel.gif]]
 
|-
 
!colspan="2"|Superstructure at or Near End Panel
 
|-
 
!colspan="2"|&nbsp;
 
|-
 
|[[Image:751.12 pedestrian overpass-superstructure near steps detail a.gif]]
 
|align="left"|Design Crieria:<br/>Fence fabric weight = 10#/lin. ft.<br/>Eff. wing area = 0.11 area/sq.ft.
 
|-
 
!Detail "A"
 
| &nbsp;
 
|}
 
  
 +
[[Category:751 LRFD Bridge Design Guidelines]]
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
==751.12.6 Culvert Guardrail (Top Mounted)==
  
|[[Image:751.12 pedestrian overpass-landing.gif]]
+
'''New Culverts'''
|[[Image:751.12 pedestrian overpass-section thru fence.gif]]
 
|-
 
!valign="top"|Landing
 
!Section thru<br/>Fence
 
|-
 
!colspan="2"|&nbsp;
 
|-
 
|colspan="2"|[[Image:751.12 pedestrian overpass-details of handrail bracket.gif]]
 
|-
 
!colspan="2"|Details of handrail Bracket
 
|-
 
!colspan="2"|&nbsp;
 
|-
 
|colspan="2"|[[Image:751.12 pedestrian overpass-rail post connection (floor plate).gif]]
 
|-
 
|colspan="2"|*4" (Min.) permitted for reduced embedment availability
 
|-
 
!colspan="2"|Rail Post Connection (Typical)
 
|-
 
!colspan="2"|&nbsp;
 
|-
 
|colspan="2"|[[Image:751.12 pedestrian overpass-plan of floor plate.gif]]
 
|-
 
!colspan="2"|Plan of Floor Plate
 
|-
 
!colspan="2"|&nbsp;
 
|-
 
|colspan="2"|[[Image:751.12 pedestrian overpass-details of expansion device gap.gif]]
 
|-
 
!colspan="2"|Details of Expansion Device Gap
 
|-
 
|colspan="2"|(**) May conflict with any proposed expansion device sidewalk, consult Structural Project Manager.
 
|-
 
!colspan="2"|&nbsp;
 
|-
 
|colspan="2"|[[Image:751.12 pedestrian overpass-typical section near splice gap.gif]]
 
|-
 
!colspan="2"|Typical Section Near Splice Gap
 
|-
 
|colspan="2" align="left"|'''Note:''' 8'-0" max. post spacing for superstructure.
 
 
(*) Locate at about 30'-0" centers with at least one splice gap between pull posts.
 
 
'''(Add the following notes to the plans.)'''<br/>The maximum spacing allowed for the braced panels (pull posts) is 100 ft.<br/>Connect the lower end of 1/2" round rod to the end of braced panel to which the stretcher bar is attached.
 
|}
 
  
 +
When a guardrail attachment is required for a new culvert, the guardrail shall be in accordance with the MASH TL-3 standard linked below. Listed below are a few of the requirements to meet MASH TL-3:
 +
:* 31-inch railing height measured between top of rail and finished grade
 +
:* 9 inches of minimum earth fill at back face of post
 +
:* 10-inch minimum clearance between headwall and post
 +
:* Guardrail shall be used on a maximum 10:1 slope. The 10:1 slope should be continued a minimum of 2 feet behind the post before using a steeper slope break.
 +
:* 6’-3” max post spacing
 +
:* Four 7/8-inch bolt pattern with 9-inch spacing in base plate
 +
:* 8-inch minimum embedment for resin-anchor option in 4 ksi concrete
 +
:* W6x9 steel post (W6x8.5 may be substituted)
 +
:* Specify Grade 36 steel for posts and base plates to match approach guardrail specifications. Anchorage is designed to resist forces for grade 50 substitution.
  
 +
Note: The 10-inch minimum clearance to headwall is to ensure the post does not contact the headwall during a collision which may create a snag point for vehicles.
  
{|border="0" cellpadding="5" cellspacing="1" align="center" style="text-align:center"
+
See [https://www.modot.org/media/16864 Standard Plan 606.50]
|+'''(112") Curved top Pedestrian Fence (Structures)'''
 
|(Optional fence detail when requested by district or railroad personnel)
 
|-
 
|[[Image:751.12 pedestrian overpass-(112in) curved top fence section a-a.gif]]
 
|-
 
!Section A-A
 
|-
 
| &nbsp;
 
|-
 
|[[Image:751.12 pedestrian overpass-(112in) curved top fence.gif]]
 
|-
 
!Curved Top Pedestrian Chain Link Fence<br/>(Galv. Steel) on Sidewalk
 
|-
 
|align="left"|'''NOTE:''' 8'-0" Max. post spacing for superstructure.
 
  
(*) Locate at about 30'-0" centers with at least one splice gap between pull posts.
+
'''Existing Culverts'''
  
The maximum spacing allowed for the braced panels (pull post) is 100 feet.<br/>Connect the lower end of 1/2" round rod to the end of braced panel to which the stretcher bar is attached.
+
See [[751.1_Preliminary_Design#751.1.3.4_Barrier_or_Railing_Type.2C_Height_and_Guidelines_for_Curb_Blockouts|EPG 751.1.3.4 Barrier or Railing Type, Height and Guidelines for Curb Blockout]] for culvert guardrail guidance.
|-
 
| &nbsp;
 
|-
 
|[[Image:751.12 pedestrian overpass-(112in) curved top fence details of expansion gap.gif]]
 
|-
 
!Details at Expansion Device Gap
 
|-
 
|align="left"|(**) May conflict with any proposed expansion device sidewalk, consult Structural Project Manager.
 
|-
 
| &nbsp;
 
|-
 
|[[Image:751.12 pedestrian overpass-(112in) curved top fence typical section near splice gap.gif]]
 
|-
 
!Typical Section Near Splice Gap
 
|-
 
|align="left"|'''Note:''' 8'-0" max. post spacing for superstructure.
 
 
(*) Locate at about 30'-0" centers with at least one splice gap between pull posts.
 
|}
 
  
  
 
[[Category:751 LRFD Bridge Design Guidelines]]
 
[[Category:751 LRFD Bridge Design Guidelines]]

Latest revision as of 12:42, 19 July 2024

To be found eligible for Federal-aid funding, new roadside safety devices should meet the crash test and evaluation criteria contained in the American Association of State Highway and Transportation Officials’ (AASHTO) Manual for Assessing Safety Hardware (MASH). Since neither FHWA nor AASHTO has a system in place to approve roadside devices, the responsibility is left with the States. In response, MoDOT has developed a MASH Implementation process. All roadside devices that are submitted after November 1, 2019, will be reviewed by the MASH Team for approval to use on Missouri roadways. Prior to November 1, 2019 roadside devices were considered using the criterion set forth in NCHRP Report 350 “Recommended Procedures for the Safety Performance Evaluation of Highway Features”. While MASH requirements are only applicable to the NHS, the following guidelines are recommended for all bridges.

See SEG 21-01, Anchoring Barriers Over Precast Panels.

AASHTO LRFD uses the term “railing” to refer to all types of bridge traffic barrier systems used on bridges. MoDOT uses the term “barrier” for solid concrete bridge railing (single-faced on the edge of roadway and dual-faced medians) and the term “railing” for barrier systems consisting of a rail(s) and supports.

Contents

751.12.1 Concrete Barriers

Type D barrier replaced Type B barrier (previously safety barrier curb) as the standard railing for bridges awarded after December 31, 2019. Similarly, Type C barrier replaced Type A barrier (previously median barrier curb). Types H and G shall be used respectively for situations where Types D and C is considered impractical.

751.12.1.jpg

Single sloped barriers have been shown to reduce vehicle climb and increase vehicle stability during redirections when compared to New Jersey shaped barriers. See the following sections for more details on standard barriers. Details for Type G have not been developed, but that does not prevent its use if need dictates.

Concrete barriers were approved for TL-3 or TL-4 test levels in accordance with the MASH 2016 standards. The required MASH 2016 test level for bridges on the National Highway System (NHS) is TL-3, but the expectation is that the TL-4 requirement will be mandated in the next publication.

Test level TL-3 is defined by AASHTO as being “generally acceptable for a wide range of high-speed arterial highways with very low mixtures of heavy vehicles and with favorable site conditions.”

Test level TL-4 is defined by AASHTO as being “generally acceptable for the majority of applications on high-speed highways, freeways, expressways, and interstate highways with a mixture of trucks and heavy vehicles”.

751.12.1.1 Material Properties

Class B-1 Concrete Epoxy Coated Reinforcing Steel
Unit weight (reinforced), wc = 0.150 kcf Yield strength, fy = 60.0 ksi
Compressive strength, f’c = 4.0 ksi Modulus of elasticity, Es = 29,000 ksi
Modular ratio, n = 8
Modulus of elasticity, Ec = 3644 ksi

751.12.1.2 General Details

Regardless of type of barrier shown the following sections are applicable for all concrete barrier types.

Top of barrier shall be built parallel to grade with barrier joints (except at end bents) normal to grade.

All exposed edges of barrier shall have either a 1/2-inch radius or a 3/8-inch bevel, unless otherwise noted.

751.12.1.2.1 Slip Forming

Conventional or slip forming may be used except for situations where slip forming is considered impractical.

See barrier elevation sheets of the barrier standard drawings for the required details.

Slip forming is impractical for prestressed double-tee bridges.

Cross Bracing C Bars

Slip forming requires two No. 5 cross bracing C bars located each side of all joints and at barrier ends.

List C bars in the Bill of Reinforcing Steel and note that bars are for the slip-formed option only.

For barrier segments on top of the bridge deck, use 12-foot C1 bars.

For barrier segments on top of the end bent wings (Type B, D or H):

For segment lengths less than 14'-4", use C2 bars with the following lengths:
Barrier Segment Length
8' to < 9' 9' to < 10' 10' to < 11' 11' to < 12' 12' to < 13' 13' to <14'-4"
Bar Length 5'-9" 6'-9" 7'-9" 8'-9" 9'-9" 10'-6"
For segment lengths 14'-4" to 18 feet, use 12-foot C1 bars.
For section greater than 18 feet, use two sets of 8-foot C2 bars.

Textured Fiberglass Bars

Slip forming requires three four-feet long No. 4 textured fiberglass bars centered at each joint.

751.12.1.2.2 Joints

See barrier elevation sheets of the barrier standard drawings for the required details.

One-fourth-inch joints are located in the barrier at locations of negative moments to prevent cracking in the barrier. Barrier joints may be formed using ¼-inch joint filler in accordance with Sec 1057 or saw cut and seal with silicone joint sealant in accordance with Sec 717. Saw cuts joints may be used with the conventional forming option.

Joints are required when decks are continuous over intermediate bents for both continuous and simple span structures. These joints are also required at the front face of integral end bents. For placement of barrier joints at integral end bents see integral end bent details.

751.12.1.2.2.1.jpg

Additional joints at 12-foot spacing from joint at intermediate bents may be required based on span lengths. The following details provide guidance on locating flexural joints near intermediate bents. This spacing will allow the full yield-line failure pattern to develop for Type D barrier. For simplicity, the 12-foot spacing shall also be used for all other concrete barrier types.

751.12.1.2.2.2.jpg

751.12.1.2.3 Plastic Waterstops

See barrier elevation sheets of the barrier standard drawings for the required details.

Plastic waterstops are typically located inside formed joints to eliminate water seepage problems on grade separations. They shall be excluded over railroads and county roads and are only required on the lower side of superelevated decks.

751.12.1.2.4 Guardrail Attachment

See barrier at end bents sheets of the barrier standard drawings for the required details.

751.12.2.6.jpg

751.12.1.2.5 Superelevation

Superelevated slope, S.E., is in decimal format for the follow calculation, i.e. use 0.04 for 4.0%.

751.12.2.5.1.jpg
751.12.2.5.2.jpg

751.12.1.2.6 Detached Wing Walls

If the detached wing wall has more than one section, see the Structural Project Manager for possible additional joints in the barrier (between sections).

The following details are for illustration purposes only:

751.12.2.6 end bents.jpg

751.12.1.2.7 Details of Mounting Light Poles on Safety Barrier Curbs

751.12.1.2.7 01 11-13-23.jpg
751.12.1.2.7 02 11-13-23.jpg

Anchor bolts and nuts shall be in accordance with ASTM F1554 Grade 55. Anchor bolts, nuts and washers shall be fully galvanized, See 751.50.H4.2.2 for additional information.

Note to Detailer: Extend slab transverse steel to edge of slab in blister region often shown with an additional detail with the slab details.

Note: Conduit not shown for clarity.

751.12.1.3 Type D and H (42ʺ and 32ʺ single sloped railing)

The 42-inch single sloped Type D barrier shall be used for railing on all new or replacement bridge projects except where sight distance is a concern. Type D meets the height requirements for both MASH 2016 TL-4 (36ʺ) and Occupational Safety and Health Administration’s OSHA (42ʺ). Type D barrier has been reviewed by the Midwest Roadside Safety Facility (MwRSF) and is compliant with MASH 2016 TL-4. This assessment is applicable for continuous and discontinuous sections of the barrier. Type D barrier shall be used on all redecks and rehabs where the full length of barrier is being replaced with exceptions as outlined in EPG 751.1.3.4 Barrier or Railing Type, Height and Guidelines for Curb Blockouts. The Type D barrier dimensions shall not be adjusted for inclusion of a wearing surface.

The 32-inch single sloped Type H barrier shall be used for railing, upon approval of the SPM or SLE, on all new or replacement bridge projects where sight distance concerns prohibit the use of Type D. Type H has the same front face slope as Type D. The minimum height for MASH 2016 TL-3 is 30 inches so there are minimal concerns with Type H for future overlays. Type H barrier has been reviewed by the Midwest Roadside Safety Facility (MwRSF) and is compliant with MASH 2016 TL-3. This assessment is applicable for continuous and discontinuous sections of the barrier. When a wearing surface is applied with the newly constructed Type H barrier, a pedestal is recommended to keep the holes for the guardrail attachment in the same location with respect to the top of the barrier.

751.12.1.3.1 Typical Section

All values may be used with both 2.0% and 3/16 inch-per-foot cross slopes.

See EPG 751.12.1.2.5 Superelevation for adjustment of values for different cross slopes.

751.12.1.3.1.jpg

751.12.1.3.2 Typical Section Reinforcement

The single R bar adds to the rigidity of the reinforcement during construction and it is believed to help prevent cracking. The single bar also appears to assist maintaining uniform reinforcement cover.

Splice length for horizontal #5 bars in barrier curb shall be 37 inches.

All bent bars are formed using stirrup bends except for the Type D #5-R1 bars.

All values may be used with both 2.0% and 3/16 inch-per-foot cross slopes.

751.12.1.3.2-001-2024.png

751.12.1.3.3 End of Barrier Reinforcement

See barrier standard drawings for the required details.

All bent bars are formed using stirrup bends.

All dimensions shown may be used with both 2.0% and 3/16 inch-per-foot cross slopes.

751.12.1.3.3.1 Type D Ending on Integral End Bents

Use when distance between upper and lower construction joint in wings is at least 28½ inches.

751.12.1.3.3.1.1 2021.jpg
751.12.1.3.3.1-002-2024.png
751.12.1.3.3.1-003-2024.png
751.12.1.3.3.1-004-2024.png
751.12.1.3.3.2 Type H Ending on Integral End Bents

Use when distance between upper and lower construction joint in wings is at least 28½ inches.

751.12.1.3.3.2.1 2021.jpg
751.12.1.3.3.2-002-2024.png
751.12.1.3.3.3 Type D Ending on Shallow Integral End Bents

Use when distance between upper and lower construction joint in wings is less than 28½ inches.

Formulas extend bars to within 1½ʺ of lower construction joint.

751.12.1.3.3.3.1 2021.jpg
751.12.1.3.3.3-002-2024.png
751.12.1.3.3.3-003-2024.png
751.12.1.3.3.3-004-2024.png
751.12.1.3.3.4 Type H Ending on Shallow Integral End Bents

Use when distance between upper and lower construction joint in wings is less than 28½ inches.

Formulas extend bars to within 1½ʺ of lower construction joint.

751.12.1.3.3.4.1 2021.jpg
751.12.1.3.3.4-002-2024.png
751.12.1.3.3.5 Type D Ending on Non-Integral End Bents

Use when distance between upper and lower construction joint in wings is at least 28½ inches.

751.12.1.3.3.5-001-2024.png
751.12.1.3.3.5-002-2024.png
751.12.1.3.3.5-003-2024.png
751.12.1.3.3.5-004-2024.png
751.12.1.3.3.6 Type H Ending on Non-Integral End Bents

Use when distance between upper and lower construction joint in wings is at least 28½ inches.

751.12.1.3.3.6-001-2024.png
751.12.1.3.3.7 Type D Ending at End of Slab (Redecks)

Splice length of #5 K12 and #5 K13 bars with #5 R-bars shall be 37 inches.

751.12.1.3.3.7-001-2024.png
751.12.1.3.3.7-002-2024.png
751.12.1.3.3.7-003-2024.png
751.12.1.3.3.7-004-2024.png
751.12.1.3.3.8 Type H Ending at End of Slab (Redecks)

Splice length of #5 K7 bars with #5 R-bars shall be 37 inches.

751.12.1.3.3.8-001-2024.png
751.12.1.3.3.8-002-2024.png

751.12.1.4 Type B (32ʺ New Jersey Shaped Railing)

The 32-inch New Jersey shaped railing, previously referred to as safety barrier curb, shall not be used on new construction projects. This includes redecks and rehabs where the full length of barrier is being replaced. Type B barrier may be replaced in kind where spot work is required (i.e., expansion joint replacements). For wearing surface projects, where the grade is not being increased more than 2 inches, the existing Type B barrier may be used in place in accordance with EPG 751.1.3.4.

751.12.1.4.1 Typical Section
751.12.1.4.1.jpg

See EPG 751.12.1.2.5 Superelevation for adjustment of values for different cross slopes.

751.12.1.4.2 Typical Section Reinforcement

The single R bar adds to the rigidity of the reinforcement during construction and it is believed to help prevent cracking. The single bar also appears to assist maintaining uniform reinforcement cover.

Splice length for horizontal #5 bars in barrier curb shall be 37 inches.

All bent bars are formed using stirrup bends except for the R1 bars.

751.12.1.4.2-001-2024.png
751.12.1.4.3 End of Barrier Reinforcement

See barrier ending on end bents sheets of the barrier standard drawings for the required details. The bars shown below are for barrier ending on wing walls; see barrier ending at end of slab sheet of the barrier standard drawings for reinforcement details for barrier ending on slabs.

Splice length of #5-K9 bars with #4 K-bars above wing walls shall be 31 inches (embedment of #5 bars controls over splice length of #4 bars).

All bent bars are formed using stirrup bends except for the K4 and K11 bars.

Ending on Integral End Bents and Semi-Deep Abutments

Use when distance between upper and lower construction joint in wings is at least 28½ inches.

751.12.1.4.3-001-2024.png
751.12.1.4.3-002-2024.png
* On skewed integral end bents, if the end K3 bars do not meet the minimum 1 1/2" clearance from the front face of the diaphragm, a K12 bar shall be substituted.
* Based on no wearing surface, adjust as needed. Example: Add 2ʺ for 2ʺ W.S.
* Also based on 8½ʺ slab, adjust as needed. Example: Subtract 1ʺ for 7½ʺ slab


Ending on Shallow Integral End Bents

Use when distance between upper and lower construction joint in wings is less than 28½ inches.

751.12.1.4.3.3 2021.jpg
751.12.1.4.3-004-2024.png

Ending on Non-Integral End Bents

Use when distance between upper and lower construction joint in wings is at least 28½ inches.

751.12.1.4.3-005-2024.png
751.12.1.4.3-006-2024.png

751.12.1.5 Type C (42ʺ Single Sloped Median)

751.12.1.5.1 Typical Section

751.12.1.5.1.jpg

751.12.1.5.2 Typical Section Reinforcement

751.12.1.5.2-001-2024.png

751.12.1.6 Type A (32ʺ New Jersey Shaped Median)

Note: Use same grade reinforcing steel in barrier as in slab.

Splice length for #5-R bars in barrier = 37".
Do not use this barrier over precast prestressed panels.
751.12.1.6-001-2024.png

Twin Bridge Median Barrier Details

751.12.1.6.1 2021.jpg

751.12.2 Two Tube Rail (Top Mounted)

38-inch Two Tube Rail

Consult the Structural Project Manager prior to use due to cost.

  • Meets TL-4 (MASH 2016)
  • May be used for decks not less than 6-1/2 inches.
  • Uses an 18-inch wide curb. If the abutment uses turned-back wings they must be 18-inches thick.
  • Acceptable for use when site distance is a concern.
  • Requires the 38-inch Two Tube Rail Transition for the bridge approaches. See STD. Plan 606.61.

32-inch Two Tube Rail

Consult the Structural Project Manager prior to use due to cost.

  • Meets TL-4 (NCHRP 350)
  • Typically used on redecks, widenings, and railing or full-length cantilever replacements where the 38-inch Two Tube Rail is not practical.
  • May be used on adjacent box beam bridges where reinforcement is embedded in the beam.
  • Acceptable for use when roadway width or site distance is a concern.
  • See EPG 751.1.3.4 Barrier or Railing Type, Height and Guidelines for Curb Blockouts for additional requirements for design speed and AADT.
  • Curb is intrinsic to TL rating and shall be used. Curb shall be used to prevent drainage over deck.
  • Requires a Bridge Anchor Section (STD. Plan 606.22) for bridge approaches minus the bearing and connector plates.

Details

Bridge Standard Drawings
Two Tube Rail

751.12.3 Median Curbs

751.12.3.1.jpg
Note: All reinforcement shown shall be epoxy coated.

Details shown are very general. Consult Design Layout for specific details for each individual structure.

751.12.3.2.jpg
751.12.3.3.jpg

751.12.4 Chain Link Fence

Design Criteria:

Dead load of fence fabric weight: 10 pounds per linear foot.

Wind load for chain link or metal fabric fence: GREATER OF 0.015 ksf acting normal to the entire surface per LRFD 13.8.2 OR 0.11 x entire surface x calculated wind pressure (11% is effective surface area per MoDOT practice).

Bridge Standard Drawings
(Fences-FEN)

751.12.5 Decorative Pedestrian Fence

751.12.5.1 Design

Decorative pedestrian fencing shall not be used without approval of the core team. Design of Decorative Pedestrian Fence is completed by consultant or contractor in accordance with LRFD 13. Bridge Pre-Qualified Products List contains a listing of decorative pedestrian fence manufacturers which have been approved for use.

General Guidelines

  • Decorative Pedestrian fences are limited to minimum 3’-6” height from top of deck or sidewalk and maximum of 8’-0” post height.
  • Decorative Pedestrian fences are limited to maximum 8’-0” post to post spacing.
  • The base plate footprint shall match that provided in the Bridge Standard Drawings. A flat base plate is provided for decorative pedestrian fences located on Type H barriers and pedestrian curbs. Bent base plates are required for installations on Type B and Type D barriers due to the limited footprint available.

751.12.6 Culvert Guardrail (Top Mounted)

New Culverts

When a guardrail attachment is required for a new culvert, the guardrail shall be in accordance with the MASH TL-3 standard linked below. Listed below are a few of the requirements to meet MASH TL-3:

  • 31-inch railing height measured between top of rail and finished grade
  • 9 inches of minimum earth fill at back face of post
  • 10-inch minimum clearance between headwall and post
  • Guardrail shall be used on a maximum 10:1 slope. The 10:1 slope should be continued a minimum of 2 feet behind the post before using a steeper slope break.
  • 6’-3” max post spacing
  • Four 7/8-inch bolt pattern with 9-inch spacing in base plate
  • 8-inch minimum embedment for resin-anchor option in 4 ksi concrete
  • W6x9 steel post (W6x8.5 may be substituted)
  • Specify Grade 36 steel for posts and base plates to match approach guardrail specifications. Anchorage is designed to resist forces for grade 50 substitution.

Note: The 10-inch minimum clearance to headwall is to ensure the post does not contact the headwall during a collision which may create a snag point for vehicles.

See Standard Plan 606.50

Existing Culverts

See EPG 751.1.3.4 Barrier or Railing Type, Height and Guidelines for Curb Blockout for culvert guardrail guidance.