751.14 Steel Superstructure

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Contents

751.14.1 General

751.14.1.1 Materials and Selection of Steel

General

Unit weight of reinforced concrete, \, \gamma_c\, = 150 lb/ft^3
 for modulus of elasticity,\, \gamma_c\, = 145 lb/ft^3
Unit weight of future wearing surface,\, \gamma_{fws}\, = 140 lb/ft^3
Compressive strength of concrete,\, f'_c \, = 4 ksi
Minimum yield strength of reinforcing steel,\, f_y \, = 60 ksi
Unit Weight of Structural Steel,\, \gamma_s \, = 490 lbs/ft^3

When calculating the weight of splice, the following simplified weight shall be used.

Weight per (A325 bolt diameter 7/8” with A563 nut) = 0.95 lb/bolt


Steel Yield Strength \,(F_y) and Tensile Strength \,(F_u)

ASTM A709 Grade 36  \,F_y = 36 ksi  \,F_u = 58 ksi
ASTM A709 Grade 50  \,F_y = 50 ksi  \,F_u = 65 ksi
ASTM A709 Grade 50W  \,F_y = 50 ksi  \,F_u = 70 ksi
ASTM A709 Grade HPS 70W*  \,F_y = 70 ksi  \,F_u = 85 ksi
(* See Project Manager for use of Fy greater than 50 ksi.)


Fasteners

Splices - ASTM A325 Bolt (7/8” diameter)\, F_{ub}=120 ksi
Diaphragms - ASTM A325 Bolt (3/4” diameter)\, F_{ub}=120 ksi


Selection of Steel

Welded Plate Girders:

Grade 50, Grade 50W, or HPS70W plate. Grade 36 may be used for webs in hybrid sections. Where appropriate for economy, hybrid sections are used for plate girder design, otherwise use homogeneous sections.


Wide Flange Beams:

Grade 50 or Grade 50W.


Diaphragms, cross frames, stiffeners, or other connection elements:

Grade 36, unless Grade 50 or Grade 50W is required by design


Splices:

Information for ASTM Grade 50 or Grade 50W is shown in this section. For Grade 36, designer shall design splice using LRFD procedure discussed in this section.


Shear Connectors:

AASHTO M169 (ASTM A108),  \,F_y = 50 ksi  \,F_u = 60 ksi

751.14.1.2 Girder Limits and Preferences

There are situations to consider when deciding to choose between a wide flange or plate girder design.

  • Curved structures or structures requiring severe camber, are more typical for welded plate girders.
  • The designer should check the availability of standard wide flange shapes.
  • Typically if wide flanges are capable for the design, a wide flange beam design will be more economical then a welded plate girder.


Maximum Section Length

Maximum girder section length shall be limited to meeting:

  • Flange shipping and erection limit of \, b_f \ge L/85, where \, b_f = flange width and \, L = section length.
  • Site accessibility restrictions (consult with District)


Additional provision for heat curving (Horizontally Curved Girders):

  • During fabrication the weight of the girder should not cause a flange stress greater than 55 percent of the flange yield strength \, (0.55F_y) when the web is laid in the horizontal position. Assume the ends are simply supported. If the flange stress exceeds \, 0.55F_y then the plans shall indicate that heat curving of the girder must be performed with the web in the vertical position.


Minimum Plate Length

10 ft. Shop flange splices should be eliminated and extra plate material used when economy indicates and span lengths permit.


Minimum Radius (Horizontally Curved Girders)

Minimum radius for heat-curved girders shall be 150 ft. In addition the minimum radius is limited by the girder section properties per LRFD 6.7.7.


Stiffeners

Longitudinal stiffeners are generally not economical in spans less than 300 ft. Consult with the State Bridge Engineer prior to using longitudinal stiffeners.

The number of different sizes of transverse stiffeners should be reduced to a minimum for stiffener widths up to 8”. This is because small plate materials of any thickness and up to 8” in width must be ordered by fabricators as bars in 20 ton lots for each size (A “bar” is generally a plate 8” wide or less). Also, it is recommended that changes in stiffener thickness should be kept to a minimum. Best practices suggest using transverse stiffener thicknesses with the same thickness as the intermediate diaphragm connection plates or bearing stiffeners but no less than required by design to limit the steel fabricator from having to order small quantities of bars or plates.


Web Depth

It is preferred to use web depths in 6” increments. Other increments may be used when required by the Design Layout (See Structural Project Manager). Note that Standard Web Splice Tables shown are provided in 2” web depth increments.

For girders analyzed as horizontally curved (see Analysis of Horizontally Curved Girders), the girder depth shall be limited in relation to the span length as follows:

\, D \ge \frac{L_{as}}{25}

Where:

\, D= steel girder depth
\, L_{as}= \, C* (Arc span length)
Where:
\, C= 1.0…simple spans:
\, C= 0.9…end continuous spans:
\, C= 0.8…interior continuous spans:


In the absence of LRFD-specific data, the following information is provided. Three spans with ratio \, n = 1.3 ± and HS20 live load were considered.


Image:751.14 three-span structure.gif
3 Span
Three Span Structure


Continuous Girders, HS20, ASTM A709 Gr. 36
Span estimate, \, L (ft)Est. Web Depth (in)
85 to 9942
100 to 11948
120 to 12954
130 to 14460
145 to 15466
155 to 16972
170 to 17978
180 to 18984
190 to 20090


Continuous Girders, HS20, ASTM A709 Gr. 50
Span estimate, L (ft)Web Depth (in)
85 to 10442
105 to 12448
125 to 13454
135 to 14460
145 to 15966
160 to 17472
175 to 17978
185 to 18984
195 to 20490


Web thickness

Minimum web thickness for plate girders = 1/2"

Web thickness increment is 1/16 inch.

Transverse stiffeners may be omitted when indicated by design and economy. A cost comparison should be made based on current average bid prices that may be obtained from the Structural Project Manager for comparable bridges.

It will usually be economical to eliminate transverse stiffeners for shallow webs (36” to 42”). For webs deeper than 42 in., a general rule of thumb is to determine the minimum web thickness without stiffeners; then, use a web thickness 1/16 inch less.


Flanges

Minimum flange dimensions are 3/4" x 12”. For shipping and erection purposes, minimum width of both compression and tension flanges shall not be less than L/85, where L is the shipping length of the girder section. This limitation is to prevent out-of-plane distortion of the girder.

Maximum flange thickness = 4”, except for HPS70W limitations and curved girders with radii less than 1000 feet.

Flange thickness increment is 1/8 inch. Flange width increment is 1 inch.

For radii less than 1000 ft. the following dimensions shall not be exceeded:

Flange Thickness = 3"
Flange Width = 30"

Note that flange transitions may be economical if the flange thickness is constant and the flange width is varied since the flanges could be cut from the same plate material. If the flange width is held constant and the flange thickness is varied, then economy could result if welded butt splices were permitted.


Structure Length

Typical Continuous Steel Structures – Integral End Bents:

Image:751.14 structure length-typical continuous steel structures-integral end bents1.gif
(*) Maximum length from End Bent to end Bent = 500 feet.

751.14.1.3 Optimizing Girder Spacing on Non-Standard Roadways

Several items shall be considered when determining the girder spacing for non-standard roadways:


General Guidelines

In general, an economical girder arrangement is one that:

Balance M & V Distribution Factors. For efficiency, it is desired for all girders to be designed for the same loads, resulting in the same section for exterior and interior girders.


Practical Constraints

Some practical constraints to consider when optimizing girder spacing:

Number of girders. For consideration of future stage construction, there may be a minimum number of girders that should be considered.

Maximum Precast Panel Span. Since precast panels are the standard, the panel span limit should not be exceeded. For cases where CIP option is used in lieu of panels, it is generally recognized that 12 ft girder spacing is a maximum practical limit to allow for future redecking.

Vertical Clearance and Deflection Requirements. It is expected that fewer girder lines would result in deeper girders. Vertical clearance or deflection constraints may dictate the use of more girder lines than optimum, or a shallower web than optimum.

Slab Overhang Limits. In order to use distribution factors provided in LRFD Table 4.6.2.2.2 for girder design, the roadway overhang shall not exceed AASHTO's specified limits, otherwise the structure shall be analyzed using a refined method of analysis specified in LRFD 4.6.3.

751.14.2 Design

751.14.2.1 Limit States and Load Factors

In general, each component shall satisfy the following equation:

\, Q = \sum \eta_i \gamma_i Q_i \le \phi R_n = R_r

Where:

\, Q= Total factored force effect
\, Q_i= Force effect
\, \eta_i= Load modifier
\, \gamma_i= Load factor
\, \phi= Resistance factor
\, R_n= Nominal resistance
\, R_r= Factored resistance


Limit States

The following limit states shall be considered for steel superstructure design:

STRENGTH – I
STRENGTH – III
STRENGTH – IV(*)
STRENGTH – V
SERVICE – II
FATIGUE
For constant amplitude fatigue threshold (∆F)TH, see LRFD Table 6.6.1.2.3-1 for applicable detail. For base metal, except noncoated weathering steel, detail category “A” (∆F)TH = 24 ksi and for base metal, noncoated weathering steel, detail category “B” (∆F)TH = 16 ksi.

Combination for loads during construction and construction loads shall be evaluated at the Strength Limit State and Service Limit State in accordance with EPG 751.2.3.2 and LRFD 3.4.2.

(*) Use for bridges with high DL to LL ratios. Typically, bridges with spans > 200 ft.

See LRFD Table 3.4.1-1 and LRFD 3.4.2 for Loads and Load Factors applied at each given limit state.


Resistance factors

STRENGTH limit states, see LRFD Article 6.5.4.2

For all other limit states, \, \phi = 1.00

751.14.2.2 Analysis Methods

MoDOT office practice generally utilizes the following:

The elastic stress at any location on the composite section due to the applied loads shall be the sum of the stresses caused by the loads applied separately at the following three stages:

Non-Composite Stage – The dead load of slab and haunching and stringer self weight shall be analyzed at this stage. This stage shall also be used for any construction loading checks. The section properties used are of the steel section only.

Long Term Composite Stage – The dead load of barrier curb, future wearing surface and any other appurtenances shall be analyzed at this stage. The section properties used are of the composite section of slab and stringer assuming an elastic modulus of 3n for the slab. Where “n” is the modular ratio.

Short Term Composite Stage – Any live loading shall be analyzed at this stage. The section properties used are of the composite section of slab and stringer assuming an elastic modulus of “n” for the slab. Where “n” is the modular ratio.

Composite regions shall be defined as regions where shear connectors are used to connect the steel section to a concrete deck. Simple spans and horizontally curved girders (see below) are designed as composite throughout.


Compact Section

Compact Design will be allowed in straight girders if holes drilled in tension flange are investigated for LRFD 6.10.1.8 Net Section Fracture.


Wind

For girder and intermediate diaphragm and cross-frame design, wind acting on the top half of girder is distributed to deck and wind on the lower half is assumed to be carried by the bottom girder flange.


Analysis of Horizontally Curved Girders

Horizontally curved girders may be analyzed as straight girders if the following criteria are met:

  • Girders are concentric
  • Bent skews \, \le 10^\circ
  • Similar girder stiffness throughout bridge width
  • \, \frac{L_{as}}{R} < 0.06   for all spans


Where:

\, R= girder radius
\, L_{as}= \, C* (Arc span length)
Where:
\, C= 1.0…simple spans:
\, C= 0.9…end continuous spans:
\, C= 0.8…interior continuous spans:


For straight girder analysis:

  • Use the arc length as the span length
  • Diaphragms and cross-frames treated as bracing members
  • Shear connectors are omitted in negative moment regions


For horizontally curved girder analysis:

  • Overturning (load-shifting) effects must be considered to contribute to the major-axis bending.
  • Diaphragms and cross frames shall be designed as primary members.
  • Design diaphragm connections to transfer forces to flanges.
  • Shear connectors provided throughout girder length
  • Lateral flange bending effects should be considered in the girder, shear connector, and flange splice design.


Note: Lateral flange bending stresses may be superimposed with stresses resulting from major-axis bending.

751.14.2.3 Intermediate Diaphragms and Cross Frames

Cross frames are located at all intermediate bents with continuous slabs.

Diaphragms or cross-frames for rolled beams shall be at least ½ the beam depth.

Girders shall be investigated for the effects of diaphragms or cross-frames for all stages of assumed construction procedures and the final condition.

Investigation shall include, but not be limited to:

  • Transfer of lateral wind loads from the bottom of the girder to the deck and from the deck to the bearings.
  • Stability of the bottom flange for all loads when it is in compression
  • Stability of the top flange in compression prior to curing of the deck


Straight Girder Layout

Typically the maximum intermediate diaphragm spacing shall be 25’-0”, unless determined otherwise for special designs.

Image:751.14 diaphragm layout for simple structures.gif
All Skews
Simple Structures
Diaphragm Layout for Simple Structures


Image:751.14 diaphragm position for continuous structures with skews thru 20 degrees.gif
Skews thru 20^\circ
Continuous Structures
Diaphragm Position for Continuous Structures with Skews Thru 20 Degrees


Image:751.14 diaphragm position for continuous structures with skews over 20 degrees.gif
Skews over 20^\circ
Continuous Structures
Diaphragm Position for Continuous Structures with Skews Over 20 Degrees


Curved Girder Layout (see Analysis of Horizontaly Curved Girders)

Maximum intermediate diaphragm spacing shall be 25’-0”, unless a lesser spacing is warranted by design. A lesser spacing may be warranted to satisfy LRFD Eq. 6.7.4.2-1 or to reduce lateral flange bending stresses.

Diaphragms shall be positioned radially and in line, except in bridges having extreme skews. Many different diaphragm spacing arrangements are possible. Attach diaphragm to a bearing stiffener where possible. The proposed diaphragm layout shall be reviewed with the Structural Project Manager prior to detailing on the plans.

A sketch of the desired diaphragm layout is given below.

Image:751.14 diaphragm layout for curved stringers1.gif
Plan of Structural Steel
Desired Diaphragm Layout for Curved Girders

751.14.2.4 End Diaphragms

General

Steel end diaphragms shall be located at all non-integral end bents and intermediate bents where continuity of the slab is broken (i.e. expansion joints). Integral end bent shall use a concrete diaphragm

Steel diaphragms for rolled beams shall be at least ½ the beam depth.

Steel diaphragms shall be investigated for all stages of assumed construction procedures and the final condition. Investigation shall include, but not be limited to:

  • Transfer of lateral wind loads from the bottom of the girder to the deck and from the deck to the bearings.
  • Stability of the bottom flange for all loads when it is in compression
  • Stability of the top flange in compression prior to curing of the deck
  • Distribution of vertical dead and live loads applied to the structure. (*)

(*) At the end of the bridge and intermediate points where the continuity of the slab is broken, the edges of the slab shall be supported by diaphragms or other suitable means as specified in LRFD 9.4.4. Top horizontal members shall be designed for vertical live and dead loads.

751.14.2.5 Part Elevation of Girders

Part Elevation of Constant Depth Girder


Image:751.14 part elevation of girder-constant depth-end span.gif
Part Elevation (End Span)


Image:751.14 part elevation of girder-constant depth-interior span.gif
Part Elevation (Interior Span)
(*)See Structural Project Manager for approval to deviate from the Maximum Girder Length of plate girder sections.
(**)Composite throughout for horizontally curved girders (see Analysis of Horizontally Curved Girders)



Part Elevation of Variable Depth Girder - Plate Girder Only


Image:751.14 part elevation of girder-variable depth girder.gif
Part Elevation

Use Variable depth section only as specified on Design Layout Sheet. Consult the Structural Project Manager for consideration of constant depth section in lieu of variable depth section based on design references or structural adequacy.

(*)See Structural Project Manager for approval to deviate from the Maximum Girder Length of plate girder sections.
(**)See Design of Welded Structures by The James F. Lincoln Arc Welding Foundation, page 5.11-19.


Image:751.14 part elevation of girder-variable depth girder-parabola.gif
Parabola - Variable Depth Girder
(*)Use 12" except for girders having bottom flange plate over 1 1/2" in thickness, then use 18".

751.14.2.6 Other Requirements

Deflection

See EPG 751.2.4.2 for Live Load deflection criteria.

Compute at 1/4 points for bridges with spans \, < 75 ft, Compute at 1/10 points for spans \, \ge 75 ft.

Camber in Horizontally Curved Girders
Rolled Beams are required to be heat curved to develop a horizontal curvature. Plate girders may either be heat curved or the flanges cut to curvature.
 
Per LRFD 6.7.7.3 heat curving causes inherent residual stresses that result in camber losses during construction and for several months of in-service use. It is not required that these camber losses be accounted for in the camber profile. Industry leaders recognize that the calculation offered by LRFD 6.7.7.3 is theoretical and often inaccurate.


Minimum Negative Flexure Deck Reinforcement

See EPG 751.10.1.5


Bearing Stiffeners

  • Bearing stiffener width shall be given in 1/2” increments and shall extend to within a 1/2” of the bottom flange.
  • Bearing stiffener thickness shall be given in 1/8” increments.
  • If the skewed stiffener option is used, make stiffeners on both sides of web for skews thru 45˚ the same size as the larger except in cases where overhang would be produced. This does not apply to end bearing stiffeners for skews over 45˚.


Diaphragms and Cross-Frames

Diaphragms and cross-frames and their connections shall:

  • Meet all applicable limit states for the calculated force effects.
  • Follow LRFD 4.6.2.7 for transfer of wind loads
  • Meet slenderness requirements of LRFD 6.8.4 or 6.9.3
  • Meet connection plate design requirements of LRFD 6.6.1.3.1
  • Be designed for stability of top flange in compression during noncomposite stage, and bottom flange for all loads when in compression.

Top horizontal members in end diaphragms shall be designed for vertical live load and dead loads.

Cross-frames or diaphragms are either considered as bracing members or primary members as discussed in the section "Analysis of Horizontally Curved Girders"

Primary Members
When diaphragms are required to resist torsional forces, such as for horizontally curved girders or straight girders with highly skewed bents, they shall be designed as primary or main members. Primary members require that forces be computed and considered in the design of both the members and their connections to the girder.


Load Rating Check

The final girder sections and steel layout should be adequate for both the design and rating analysis. It is recommended to perform the load rating before finalizing the girder design.

751.14.3 Splice Design

751.14.3.1 Field Bolted Splice Design

General

In continuous spans, splices should be made at or near points of dead load contraflexure excluding future wearing surface. Web and Flange splices in areas of stress reversal shall be investigated for both positive and negative flexure.

In both web and flange splices, there shall not be less than two rows of bolts on each side of the joint. Oversize or slotted holes shall not be used in either the member or the splice plates at bolted splices.

Bolted splices for flexural members shall be designed using slip-critical connections as specified in LRFD 6.13.2.1.1. The connections shall also be proportioned to prevent slip during the erection of the steel and during the casting of the concrete deck.

The tensile stress on the flange should be checked for net fracture per LRFD 6.10.1.8.

In bolted slip-critical connections subject to shear, the load is transferred between the connected parts by friction up to a certain level of force that is dependent upon the total clamping force on the faying surfaces and the coefficient of friction of the faying surfaces. As loading is increased to a level in excess of the frictional resistance between the faying surfaces, slip occurs, but failure in the sense does not occur. As a result, slip critical connections are able to resist even greater loads by shear and bearing against the connected material. The strength of the connection is not related to the slip load. Slip resistance, shear resistance and bending shall be computed separately. Any potential greater resistance due to combined effect is ignored.


Bolt Design

Slip Resistance

Splices shall be designed as slip critical connections with Class B surface preparation and standard holes. Slip shall be checked against the maximum of the Service-II limit stresses and the Strength-I construction stresses due to slab pouring sequences. All splice bolts shall be 7/8” diameter ASTM A325 high strength bolts with a minimum pretension of 39 kips upon girder erection.


Shear Resistance

The Bolt Shear Resistance shall be adequate to resist loads at the Strength-I limit state. (see Loads section under Flange Splice Plate Design)

If a filler plate not less than 0.25” in thickness is used in a flange splice then the Bolt Shear Resistance shall be reduced by the following factor:

\, R = \frac {(1 + \gamma)}{(1 + 2 \gamma)}

Where:

\, \gamma= \, \frac {A_f}{A_p}
\, A_f= sum of the area of the fillers on the top and bottom of the connected plate \, (in^2)
\, A_p= smaller of either the connected plate area or the sum of the splice plate areas on the top and bottom of the connected plate \, (in^2)

If the distance between extreme fasteners on one side of a flange splice (joint length) is greater than 50 inches then the Bolt Shear Resistance shall be reduced by 20%. Excluding the threads from the shear plane (when applicable) in order to reduce the overall length of a joint is preferred over reducing the Bolt Shear Resistance for large joint lengths.


Min. splice plate thickness:Image:751.14 critical dimensions for checking thread exclusion in .875in dia high strength bolted connections.gif
\, \le \frac {5}{8}^{\prime\prime} \RightarrowBolt threads included
\, \ge \frac {3}{4}^{\prime\prime} \RightarrowBolt threads excluded
 
 
 Note:The washer may be located under the nut or bolt head.
 Critical dimensions for checking thread exclusion
in 7/8” diameter high strength bolted connections.

Threads may be excluded from the shear plane when the minimum splice plate thickness at the joint is greater than 5/8”. Otherwise, the bolt threads shall be assumed to be included in the shear plane.

Thread Embedment, \, T_e = \, T - \, H - washer height – (stick-out)

\, T_{e, max} = 1.5" - 55/64" - 0" - 0" = 0.641" or 3/4" rounded up to the nearest 1/8”.


Flange Bolt Patterns

The minimum distance from the center of any fastener in a standard hole to a sheared or thermally cut edge shall be 1 1/2 inches for 7/8” diameter fasteners. The minimum distance between centers of fasteners in standard holes shall be three times the diameter of the fastener, but shall not be less than 3 inches parallel to the line of force for 7/8” diameter fasteners. The minimum edge distance shall be 2 inches for top flange outer splice plates to allow for panel clearance.

Uniform bolt patterns are preferred in all cases except that a staggered pattern may be used for flanges that are 14 and 15 inches wide. A staggered bolt pattern reduces the distance between rows of bolts so panels can be placed along the edges of the plate.

Bolt tightening clearances may become a problem for thick flanges. Generally, if the flange inner splice plate thickness is less than 1.5” then construction clearances can be assumed to be adequate. Otherwise, a thorough review is required to ensure that a 2.5” diameter socket with 1/16” clearance can be used. If the inner splice plate thickness cannot be reduced the web bolt pattern can be modified.


Image:751.14 flange bolt patterns-uniform bolt pattern.gif
Uniform Bolt Pattern


Image:751.14 flange bolt patterns-staggered bolt pattern.gif
Staggered Bolt Pattern


Flange Splice Plate Design

Flange Width Transitions

When the width of the flanges being spliced differs by more than 2”, the larger flange shall be beveled as shown below.


Image:751.14 flange width transition at splice.gif
Flange Width Transition at Splice


Flange Splice Dimensions

  1. Minimum thickness of splice plate = 3/8”
  2. Splice plate thickness increment = 1/8”
  3. At the strength limit state, if the gross areas of the outer and inner splice plates vary by less than 10% then the shear force can be distributed by double shear. Otherwise, the shear force must be distributed to each shear plane by the percentage of the gross area of the plate in contact with the shear plane from the total gross area of splice plates. (Note: Double shear can be assumed at the service limit state for all cases)
  4. The total gross area of the splice plates shall be greater than the gross area of the smaller flange.
  5. Bolt holes are considered to be 1” in diameter for the purpose of determining the net flange or splice area.
  6. Inner splice plates shall be symmetric for uniform bolt patterns.


Loads

  • Strength I - Splice plates shall be designed to resist a minimum design stress equal to the average of the factored elastic flexural stress at the mid-depth of the flange and the yield strength of the flange \,(F_{yf}), but shall not be less than \, 0.75 F_{yf}.
  • Service II – Use factored loading to determine design force.
  • Construction – Use factored loading to determine design force.
  • Fatigue – Use factored loading to determine design stress range.


Resistance

The nominal flexural resistance \, (F_n) of the flange at the point of splice at the strength limit state shall be assumed to be equal to the specified minimum yield strength of the flange \, (F_{yf}). For hybrid sections, a hybrid factor \, (R_h) shall be used to increase the stress seen by the flange when the factored elastic flexural stress exceeds \, F_{yw} at the top or bottom of the web.

Flange splice plates shall be checked for:

  • Tensile Resistance @ Strength-I Limit State
Yielding of Gross Section
Fracture of Net Section
Block Shear Rupture of Net Section
  • Compressive Resistance @ Strength-I Limit State
  • Fatigue Resistance @ Fatigue and Fracture Limit State
  • Permanent Deflection under Construction loads

Note: The last two checks may be ignored if the sum of the gross splice plate areas is greater than the gross area of the flange.


Girder flange shall be checked for:

  • Tensile Resistance @ Strength-I Limit State
Fracture of Net Section
Block Shear Rupture of Net Section
  • Bearing Resistance @ Strength-I Limit State


Web Splice Plate Design

Web Splice Dimensions

  1. Webs shall be spliced symmetrically by plates on each side.
  2. These plates shall extend as near as practical for the full depth between flanges.
  3. The thickness of the web splice plates shall be 3/8”. The total gross area of the splice plates shall be greater than the gross area of the smaller web at splice.
  4. Bolt holes are considered to be 1” in diameter for the purpose of determining the net web or splice area.


Loads

Web splice plates and their connections shall be designed for shear, the moment due to the eccentricity of the shear at the point of splice, and the portion of the flexural moment assumed to be resisted by the web at the point of splice.

  • Strength I - If Vu>0.5Vr, then the design shear (Vuw) shall be equal to the average of the factored shear loading (Vu) and the factored shear resistance (Vr) of the smaller web. Otherwise, Vuw=1.5Vu. The design moment shall be calculated using the design stresses determined for flange design.
  • Service II – Use the factored loading to determine the design shear and moment.
  • Construction – Use the factored loading to determine the design moment and shear.
  • Fatigue – Use the factored loading to determine the design stress range.


Resistance

The factored shear resistance \, (V_r) of the web shall be determined as specified in LRFD 6.12.1.2.3. For hybrid sections the web shall resist only the stress not exceeding the yield strength of the web \, (F_{yw}). A hybrid factor \, (R_h) shall be used to reduce the stress seen by the web when the factored elastic flexural stress exceeds \, F_{yw} at the top or bottom of the web.

Web splice plates shall be checked for:

  • Shear Resistance @ Strength-I Limit State
Yielding of Gross Section
Fracture of Net Section
Block Shear Rupture of Net Section
  • Flexural Resistance @ Strength-I Limit State
  • Fatigue Resistance @ Fatigue and Fracture Limit State
  • Permanent Deflection under construction loads

Note: The last two checks may be ignored if the sum of the gross splice plate areas is greater than the gross area of the web.

Girder web shall be checked for:

  • Bearing Resistance @ Strength-I Limit State


Design Tools

Field Flange Splice Tables

The flange tables were developed assuming a symmetric girder section with the tension flange near yield. The flange splice plates were designed to carry this tension force along with the associated compression force found on the opposing flange. Net fracture of the flange is eliminated by limiting the factored tensile stress, \, f_t, to the maximums allowed in the table below. When the flange section or steel grade changes at a splice, use the narrower flange. For flanges with the same width, the smaller flange strength may be used from the table as shown below. Note: The tables are not designed for the lateral bending effects induced in horizontally curved bridges. Lateral forces may increase the design bolt force above the value used in the tables.

Which flange should be used to enter in the tables?

A.Grade 50W – 18” x 2”vs.B.Grade 70W – 18” x 1.375”
50ksi x 18” x 2” = 1800 k>70ksi x 18” x 1.375” = 1733 k

Use Flange B from the table (50W splice plate)


Field Web Splice Tables

The dimensions of the web splices shown in the tables are based on the assumption that the factored shear force \, (V_u) is equal to the web’s unstiffened shear capacity \, (V_r). Also, the moment required to be resisted by the web \, (M_u) is assumed to be half of the elastic web moment capacity \, (0.5 M_{cap}) . If the design shear \, (V_{uw}) is greater than the unstiffened shear capacity, \, V_r, (i.e, stiffened webs) then the web splice shall be designed in accordance with LRFD 6.13.6.1.4b. Flange splices shall be checked to ensure that they can resist the entire moment applied to the girder section at the centerline of the splice, or the web and flange splices will have to be designed in accordance with LRFD 6.13.6.1.4b & c. Lateral bending effects from horizontal curvature need not be considered in the design of the web splice.

Maximum allowable gross tensile stress in flange at splice per
LRFD 6.10.1.8. (*)
Flange Width Flange Grade
50 50W 70W
12”45.549.063.0
13”46.249.764.0
14”46.049.663.7
15”46.65064.5
16”40.944.156.7
17”41.745.057.8
18”42.545.758.8
19”43.146.459.7
20”43.747.060.5
21”44.247.661.2
22”39.742.855.0
23”40.443.555.9
24”40.944.156.7
(*) Lower stresses will not fracture the net section when using the Flange Splice tables.
Maximum stresses are dependant on bolt pattern.

751.14.3.2 Plate Girder - Flange Splice Tables

Flange Plate Size: 12" thru 24" (2, 4 or 6 rows of Bolts) ASTM A709, Grade 50 and 50W Flanges, Grade 50 and 50W Splice


Image:751.14 FLANGE PLATE SIZE 12in thru 24in (2 4 or 6 rows of Bolts).gif
Note: For staggered bolt patterns the spacing shown above is for the edge rows of bolts.


Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
12 x 3/4"< 1/4"120.50036.540.62536.53650024136.7
other120.50054.540.62554.53680036204.2
12 x 7/8"< 1/4"120.62542.54.50.62542.52.756.560028184.8
other120.62560.54.50.75060.52.756.590040282.5
12 x 1"< 1/4"120.62542.54.50.75042.52.756.560028198.3
other120.62566.54.50.75066.52.756.5100044310.5
12 x 1 1/8" *< 1/4"120.75042.550.75042.52.5760028225.4
other120.75060.550.75060.52.5790040321.1
12 x 1 1/4" *< 1/4"120.75048.550.75048.52.5770032257.3
other120.75066.550.75066.52.57100044352.9
12 x 1 3/8" *< 1/4"120.87554.550.87554.52.5780036331.7
other120.87566.551.00066.52.57100044428.4
12 x 1 1/2" *< 1/4"120.87554.551.00054.52.5780036351.0
other120.87566.551.00066.52.57100044428.4
12 x 1 5/8" *< 1/4"121.00054.551.12554.52.5780036393.5
other121.00066.551.12566.52.57100044480.2
12 x 1 3/4" *< 1/4"121.00060.551.12560.52.5790040436.9
other121.00072.551.12572.52.57110048523.6
12 x 1 7/8" *< 1/4"121.12566.551.25066.52.57100044532.1
other121.12572.551.25072.52.57110048580.1
12 x 2" *< 1/4"121.25066.551.37566.52.57100044583.9
other121.25078.551.37578.52.57120052689.4
12 x 2 1/8" *< 1/4"121.25072.551.37572.52.57110048636.7
other121.25084.551.37584.52.57130056742.1
12 x 2 1/4" *< 1/4"121.37578.551.50078.52.57120052750.6
other121.37590.551.50090.52.57140060865.4
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
13 x 3/4"< 1/4"130.50036.540.75036.53.5650024152.2
other130.50054.540.75054.53.5680036227.4
13 x 7/8"< 1/4"130.62542.54.50.75042.53.256.560028205.9
other130.62566.54.50.87566.53.256.5100044343.5
13 x 1"< 1/4"130.62548.54.50.87548.53.256.570032250.4
other130.62572.54.50.87572.53.256.5110048374.5
13 x 1 1/8" *< 1/4"130.75048.550.87548.53770032284.8
other130.75066.550.87566.537100044390.7
13 x 1 1/4" *< 1/4"130.75048.550.87548.53770032284.8
other130.75066.550.87566.537100044390.7
13 x 1 3/8" *< 1/4"130.75054.551.00054.53780036339.4
other130.75066.551.00066.537100044414.2
13 x 1 1/2" *< 1/4"130.87554.551.12554.53780036383.9
other130.87572.551.12572.537110048510.7
13 x 1 5/8" *< 1/4"131.00060.551.25060.53790040475.5
other131.00072.551.25072.537110048569.8
13 x 1 3/4" *< 1/4"131.00066.551.25066.537100044522.7
other131.00078.551.25078.537120052617.0
13 x 1 7/8" *< 1/4"131.12572.551.25072.537110048603.2
other131.12584.551.25084.537130056703.1
13 x 2" *< 1/4"131.25078.551.37578.537120052717.2
other131.25090.551.50090.537140060859.0
13 x 2 1/8" *< 1/4"131.25078.551.50078.537120052745.0
other131.25090.551.50090.537140060859.0
13 x 2 1/4" *< 1/4"131.37584.551.62584.537130056870.9
other131.37596.551.62596.537150064994.6
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Staggered Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
14 x 3/4"< 1/4"140.50021.55.50.62521.525212.524107.4
other140.50033.55.50.62533.525412.540169.8
14 x 7/8"< 1/4"140.50027.55.50.75027.525312.532149.3
other140.50039.55.50.75039.525512.548216.4
14 x 1"< 1/4"140.62527.55.50.75027.525312.532163.0
other140.62545.55.50.75045.525612.556272.5
14 x 1 1/8" *< 1/4"140.75027.55.50.75027.525312.532176.6
other140.75039.55.50.75039.525512.548255.6
14 x 1 1/4" *< 1/4"140.87533.55.50.87533.525412.540245.8
other140.87539.55.51.00039.525512.548306.0
14 x 1 3/8" *< 1/4"140.87533.55.51.00033.525412.540258.9
other140.87545.55.51.00045.525612.556353.2
14 x 1 1/2" *< 1/4"140.87533.55.51.12533.525412.540271.9
other140.87545.55.51.12545.525612.556370.9
14 x 1 5/8" *< 1/4"141.00039.55.51.12539.525512.548341.0
other141.00045.55.51.12545.525612.556393.5
14 x 1 3/4" *< 1/4"141.12539.55.51.25039.525512.548376.0
other141.12545.55.51.25045.525612.556433.8
14 x 1 7/8" *< 1/4"141.25045.55.51.25045.525612.556456.4
other141.25051.55.51.25051.525712.564517.2
14 x 2" *< 1/4"141.25045.55.51.37545.525612.556474.1
other141.25051.55.51.37551.525712.564537.2
14 x 2 1/8" *< 1/4"141.37551.55.51.37551.525712.564562.8
other141.37557.55.51.37557.525812.572628.9
14 x 2 1/4" *< 1/4"141.50051.55.51.50051.525712.564608.4
other141.50063.55.51.50063.525912.580751.2
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Staggered Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
15 x 3/4"< 1/4"150.50027.56.50.50027.526312.532139.6
other150.50039.56.50.50039.526512.548202.4
15 x 7/8"< 1/4"150.50027.56.50.62527.526312.532152.2
other150.50039.56.50.62539.526512.548220.6
15 x 1"< 1/4"150.62533.56.50.62533.526412.540204.2
other150.62545.56.50.62545.526612.556279.0
15 x 1 1/8"< 1/4"150.62533.56.50.75033.526412.540219.7
other150.62551.56.50.75051.526712.564340.1
15 x 1 1/4" *< 1/4"150.75033.56.50.87533.526412.540252.9
other150.75045.56.50.87545.526612.556345.1
15 x 1 3/8" *< 1/4"150.87533.56.50.87533.526412.540270.7
other150.87545.56.50.87545.526612.556369.3
15 x 1 1/2" *< 1/4"150.87539.56.51.00039.526512.548338.2
other150.87545.56.51.00045.526612.556390.3
15 x 1 5/8" *< 1/4"151.00039.56.51.00039.526512.548359.2
other151.00051.56.51.00051.526712.564469.7
15 x 1 3/4" *< 1/4"151.12545.56.51.12545.526612.556459.6
other151.12551.56.51.12551.526712.564520.8
15 x 1 7/8" *< 1/4"151.12545.56.51.25045.526612.556480.6
other151.12551.56.51.25051.526712.564544.5
15 x 2" *< 1/4"151.25051.56.51.25051.526712.564571.9
other151.25057.56.51.25057.526812.572639.1
15 x 2 1/8" *< 1/4"151.25051.56.51.37551.526712.564595.7
other151.25057.56.51.37557.526812.572665.6
15 x 2 1/4" *< 1/4"151.37551.56.51.37551.526712.564623.0
other151.37563.56.51.37563.526912.580769.2
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
16 x 3/4"< 1/4"160.50024.570.50024.52631332134.6
other160.50036.570.50036.52651348200.9
16 x 7/8"< 1/4"160.50024.570.50024.52631332134.6
other160.50042.570.50042.52661356234.0
16 x 1"< 1/4"160.62530.570.62530.52641340200.2
other160.62542.570.75042.52661356300.3
16 x 1 1/8"< 1/4"160.62530.570.75030.52641340215.3
other160.62548.570.75048.52671364342.7
16 x 1 1/4" *< 1/4"160.75030.570.75030.52641340232.6
other160.75042.570.75042.52661356324.4
16 x 1 3/8" *< 1/4"160.75030.570.87530.52641340247.7
other160.75042.570.87542.52661356345.4
16 x 1 1/2" *< 1/4"160.87536.570.87536.52651348317.3
other160.87548.570.87548.52671364421.8
16 x 1 5/8" *< 1/4"160.87536.571.00036.52651348335.4
other160.87548.571.00048.52671364445.9
16 x 1 3/4" *< 1/4"161.00036.571.12536.52651348374.2
other161.00048.571.12548.52671364497.5
16 x 1 7/8" *< 1/4"161.12542.571.12542.52661356459.9
other161.12554.571.12554.52681372590.0
16 x 2" *< 1/4"161.12542.571.25042.52661356481.0
other161.12554.571.25054.52681372617.0
16 x 2 1/8" *< 1/4"161.25048.571.25048.52671364576.5
other161.25060.571.25060.52691380719.3
16 x 2 1/4" *< 1/4"161.25048.571.37548.52671364600.6
other161.25060.571.37560.52691380749.4
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
17 x 3/4"< 1/4"170.50024.570.50024.52.5631332138.1
other170.50036.570.62536.52.5651348224.1
17 x 7/8"< 1/4"170.50024.570.62524.52.5631332150.2
other170.50042.570.62542.52.5661356261.1
17 x 1"< 1/4"170.62530.570.62530.52.256.541340205.6
other170.62548.570.62548.52.256.571364327.3
17 x 1 1/8"< 1/4"170.62536.570.75036.52.256.551348264.2
other170.62548.570.75048.52.256.571364351.3
17 x 1 1/4" *< 1/4"170.75030.570.87530.52741340254.2
other170.75042.570.87542.52761356354.5
17 x 1 3/8" *< 1/4"170.87536.570.87536.52751348326.3
other170.87548.570.87548.52771364433.8
17 x 1 1/2" *< 1/4"170.87536.571.00036.52751348344.5
other170.87548.571.00048.52771364457.9
17 x 1 5/8" *< 1/4"171.00042.571.00042.52761356426.8
other171.00054.571.00054.52781372547.5
17 x 1 3/4" *< 1/4"171.12542.571.12542.52761356473.5
other171.12554.571.12554.52781372607.4
17 x 1 7/8" *< 1/4"171.12548.571.12548.52771364540.4
other171.12554.571.12554.52781372607.4
17 x 2" *< 1/4"171.25048.571.25048.52771364593.7
other171.25060.571.25060.52791380740.8
17 x 2 1/8" *< 1/4"171.25048.571.37548.52771364617.8
other171.25060.571.37560.52791380770.8
17 x 2 1/4" *< 1/4"171.37554.571.37554.52781372727.1
other171.37566.571.37566.527101388887.4
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
18 x 3/4"< 1/4"180.50024.580.50024.52631432148.5
other180.50042.580.50042.52661456258.1
18 x 7/8"< 1/4"180.50030.580.50030.52641440185.0
other180.50048.580.50048.52671464294.6
18 x 1"< 1/4"180.50036.580.62536.52651448242.3
other180.50048.580.62548.52671464322.1
18 x 1 1/8"< 1/4"180.62536.580.75036.52.256.5513.548286.2
other180.62554.580.75054.52.256.5813.572427.7
18 x 1 1/4" *< 1/4"180.75036.580.75036.52.5751348309.5
other180.75048.580.75048.52.5771364411.5
18 x 1 3/8" *< 1/4"180.75036.580.87536.52.5751348330.2
other180.75048.580.87548.52.5771364439.0
18 x 1 1/2" *< 1/4"180.87542.580.87542.52.5761356411.7
other180.87554.580.87554.52.5781372528.2
18 x 1 5/8" *< 1/4"180.87542.581.00042.52.5761356435.8
other180.87554.581.00054.52.5781372559.1
18 x 1 3/4" *< 1/4"181.00048.581.00048.52.5771364528.4
other181.00054.581.00054.52.5781372593.8
18 x 1 7/8" *< 1/4"181.00048.581.12548.52.5771364555.9
other181.00054.581.12554.52.5781372624.8
18 x 2" *< 1/4"181.12554.581.12554.52.5781372659.5
other181.12560.581.12560.52.5791380732.2
18 x 2 1/8" *< 1/4"181.25054.581.25054.52.5781372725.2
other181.25066.581.25066.52.57101388885.0
18 x 2 1/4" *< 1/4"181.25054.581.37554.52.5781372756.1
other181.25066.581.37566.52.57101388922.7
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
19 x 7/8"< 1/4"190.50030.58.50.50030.526414.540193.7
other190.50048.58.50.50048.526714.564308.4
19 x 1"< 1/4"190.50036.58.50.62536.526514.548253.9
other190.50054.58.50.62554.526814.572379.4
19 x 1 1/8"< 1/4"190.62536.58.50.75036.52.256.551448300.5
other190.62554.58.50.75054.52.256.581472449.0
19 x 1 1/4" *< 1/4"190.75036.58.50.75036.52.57513.548325.1
other190.75048.58.50.75048.52.57713.564432.1
19 x 1 3/8" *< 1/4"190.75036.58.50.87536.52.57513.548347.0
other190.75048.58.50.87548.52.57713.564461.4
19 x 1 1/2" *< 1/4"190.87542.58.50.87542.52.57613.556432.8
other190.87554.58.50.87554.52.57813.572555.2
19 x 1 5/8" *< 1/4"190.87542.58.51.00042.52.57613.556458.4
other190.87554.58.51.00054.52.57813.572588.1
19 x 1 3/4" *< 1/4"191.00048.58.51.00048.52.57713.564555.9
other191.00060.58.51.00060.52.57913.580693.6
19 x 1 7/8" *< 1/4"191.00048.58.51.12548.52.57713.564585.1
other191.00060.58.51.12560.52.57913.580730.1
19 x 2" *< 1/4"191.12554.58.51.12554.52.57813.572694.3
other191.12566.58.51.12566.52.571013.588847.3
19 x 2 1/8" *< 1/4"191.12554.58.51.25054.52.57813.572727.1
other191.12566.58.51.25066.52.571013.588887.4
19 x 2 1/4" *< 1/4"191.25060.58.51.25060.52.57913.580848.0
other191.25072.58.51.25072.52.571113.5961016.3
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
20 x 7/8"< 1/4"200.50030.590.50030.52641540202.3
other200.50048.590.50048.52671564322.1
20 x 1"< 1/4"200.50036.590.62536.52651548265.5
other200.50054.590.62554.52681572396.8
20 x 1 1/8"< 1/4"200.62542.590.62542.52.256.5614.556339.4
other200.62560.590.62560.52.256.5914.580483.4
20 x 1 1/4" *< 1/4"200.75036.590.75036.52.5751448340.6
other200.75054.590.75054.52.5781472508.8
20 x 1 3/8" *< 1/4"200.75042.590.87542.52.5761456423.8
other200.75054.590.87554.52.5781472543.6
20 x 1 1/2" *< 1/4"200.87542.590.87542.52.5761456453.9
other200.87560.590.87560.52.5791480646.4
20 x 1 5/8" *< 1/4"200.87548.591.00048.52.5771464549.0
other200.87554.591.00054.52.5781472617.0
20 x 1 3/4" *< 1/4"201.00048.591.00048.52.5771464583.4
other201.00060.591.00060.52.5791480727.9
20 x 1 7/8" *< 1/4"201.00054.591.12554.52.5781472690.4
other201.00060.591.12560.52.5791480766.5
20 x 2" *< 1/4"201.12560.591.12560.52.5791480809.4
other201.12566.591.12566.52.57101488889.7
20 x 2 1/8" *< 1/4"201.12560.591.25060.52.5791480848.0
other201.12566.591.25066.52.57101488932.2
20 x 2 1/4" *< 1/4"201.25066.591.25066.52.57101488979.3
other201.25078.591.25078.52.5712141041156.1
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
21 x 7/8"< 1/4"210.50036.59.50.50036.526515.548252.6
other210.50054.59.50.50054.526815.572377.5
21 x 1"< 1/4"210.62536.59.50.62536.52.256.551548304.4
other210.50060.59.50.62560.526915.580459.9
21 x 1 1/8"< 1/4"210.62542.59.50.62542.52.256.561556354.5
other210.62560.59.50.75060.52.256.591580545.6
21 x 1 1/4" *< 1/4"210.75042.59.50.75042.52.57614.556414.7
other210.75054.59.50.75054.52.57814.572532.0
21 x 1 3/8" *< 1/4"210.75042.59.50.87542.52.57614.556443.4
other210.75054.59.50.87554.52.57814.572568.7
21 x 1 1/2" *< 1/4"210.87548.59.50.87548.52.57714.564542.2
other210.87560.59.50.87560.52.57914.580676.4
21 x 1 5/8" *< 1/4"210.87548.59.51.00048.52.57714.564574.8
other210.87560.59.51.00060.52.57914.580717.2
21 x 1 3/4" *< 1/4"211.00054.59.51.00054.52.57814.572686.6
other211.00066.59.51.00066.52.571014.588837.9
21 x 1 7/8" *< 1/4"211.00054.59.51.12554.52.57814.572723.3
other211.00066.59.51.12566.52.571014.588882.7
21 x 2" *< 1/4"211.12560.59.51.12560.52.57914.580848.0
other211.12572.59.51.12572.52.571114.5961016.3
21 x 2 1/8" *< 1/4"211.12560.59.51.25060.52.57914.580888.7
other211.12572.59.51.25072.52.571114.5961065.2
21 x 2 1/4" *< 1/4"211.25066.59.51.25066.52.571014.5881026.5
other211.25078.59.51.25078.52.571214.51041211.8
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
22 x 1"< 1/4"220.62524.5100.62524.52632348228.0
other220.62536.5100.62536.52652372340.1
22 x 1 1/8"< 1/4"220.62530.5100.75030.52642360305.7
other220.62542.5100.75042.52662384426.3
22 x 1 1/4" *< 1/4"220.75024.5100.75024.52632348264.4
other220.75036.5100.75036.52652372394.4
22 x 1 3/8" *< 1/4"220.75030.5100.87530.52642360351.1
other220.75036.5100.87536.52652372420.3
22 x 1 1/2" *< 1/4"220.87530.5101.00030.52642360396.5
other220.87542.5101.00042.52662384552.8
22 x 1 5/8" *< 1/4"220.87530.5101.00030.52642360396.5
other220.87542.5101.00042.52662384552.8
22 x 1 3/4" *< 1/4"221.00036.5101.12536.52652372529.0
other221.00042.5101.12542.52662384616.1
22 x 1 7/8" *< 1/4"221.00036.5101.12536.52652372529.0
other221.00042.5101.12542.52662384616.1
22 x 2" *< 1/4"221.12542.5101.25042.52662384679.4
other221.12548.5101.25048.52672396775.4
22 x 2 1/8" *< 1/4"221.12542.5101.25042.52662384679.4
other221.12548.5101.25048.52672396775.4
22 x 2 1/4" *< 1/4"221.25042.5101.37542.52662384742.6
other221.25054.5101.37554.526823108952.6
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
23 x 1"< 1/4"230.50030.510.50.62530.526423.2560270.0
other230.50042.510.50.62542.526623.2584376.6
23 x 1 1/8"< 1/4"230.62530.510.50.75030.52.256.542360317.5
other230.62542.510.50.75042.52.256.562384442.9
23 x 1 1/4" *< 1/4"230.75030.510.50.75030.52.256.542360342.4
other230.75036.510.50.75036.52.256.552372410.0
23 x 1 3/8" *< 1/4"230.75030.510.50.87530.52.256.542360365.1
other230.75042.510.50.87542.52.256.562384509.1
23 x 1 1/2" *< 1/4"230.87530.510.50.87530.52.256.542360390.0
other230.87542.510.50.87542.52.256.562384543.8
23 x 1 5/8" *< 1/4"230.87536.510.51.00036.52.256.552372494.0
other230.87542.510.51.00042.52.256.562384575.4
23 x 1 3/4" *< 1/4"231.00036.510.51.12536.52.256.552372551.0
other231.00042.510.51.12542.52.256.562384641.7
23 x 1 7/8" *< 1/4"231.00036.510.51.12536.52.256.552372551.0
other231.00048.510.51.12548.52.256.572396732.4
23 x 2" *< 1/4"231.12542.510.51.25042.52.256.562384708.0
other231.12548.510.51.25048.52.256.572396808.1
23 x 2 1/8" *< 1/4"231.12542.510.51.25042.52.256.562384708.0
other231.12554.510.51.25054.52.256.5823108908.2
23 x 2 1/4" *< 1/4"231.25048.510.51.37548.52.256.572396883.7
other231.25054.510.51.37554.52.256.5823108993.2
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
24 x 1"< 1/4"240.50030.5110.62530.526423.560279.7
other240.62542.5110.62542.52.256.5623.2584426.3
24 x 1 1/8"< 1/4"240.62530.5110.75030.52.256.5423.2560329.4
other240.62548.5110.75048.52.256.5723.2596524.4
24 x 1 1/4" *< 1/4"240.75030.5110.75030.52.5742360355.4
other240.75042.5110.75042.52.5762384495.6
24 x 1 3/8" *< 1/4"240.75030.5110.87530.52.5742360379.2
other240.75042.5110.87542.52.5762384528.7
24 x 1 1/2" *< 1/4"240.87536.5110.87536.52.5752372485.0
other240.87542.5110.87542.52.5762384564.9
24 x 1 5/8" *< 1/4"240.87536.5111.00036.52.5752372513.5
other240.87542.5111.00042.52.5762384598.0
24 x 1 3/4" *< 1/4"241.00036.5111.12536.52.5752372573.0
other241.00048.5111.12548.52.5772396761.7
24 x 1 7/8" *< 1/4"241.00042.5111.12542.52.5762384667.3
other241.00048.5111.12548.52.5772396761.7
24 x 2" *< 1/4"241.12542.5111.25042.52.5762384736.6
other241.12554.5111.25054.52.57823108944.9
24 x 2 1/8" *< 1/4"241.12548.5111.25048.52.5772396840.7
other241.12554.5111.25054.52.57823108944.9
24 x 2 1/4" *< 1/4"241.25048.5111.37548.52.5772396919.8
other241.25060.5111.37560.52.579231201147.6
* Bolt threads are EXCLUDED from shear plane


Flange Plate Size: 12" thru 24" (2-6 rows of Bolts) ASTM A709, Grade 70W Flange, Grade 50W Splice


Image:751.14 FLANGE PLATE SIZE 12in thru 24in (2 4 or 6 rows of Bolts).gif
Note: For staggered bolt patterns the spacing shown above is for the edge rows of bolts.


Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
12 x 3/4"< 1/4"120.75042.550.75042.52.5760028225.4
other120.75072.550.75072.52.5790040377.2
12 x 7/8" *< 1/4"120.75042.550.75042.52.5760028225.4
other120.75066.550.87566.52.57100044376.5
12 x 1" *< 1/4"120.87548.550.87548.52.5770032295.1
other120.87572.551.00072.52.57110048467.0
12 x 1 1/8" *< 1/4"120.87554.551.00054.52.5780036351.0
other120.87578.551.00078.52.57120052505.7
12 x 1 1/4" *< 1/4"121.00054.551.12554.52.5780036393.5
other121.00078.551.12578.52.57120052566.9
12 x 1 3/8" *< 1/4"121.12560.551.25060.52.5790040484.0
other121.12584.551.25084.52.57130056676.2
12 x 1 1/2" *< 1/4"121.25066.551.37566.52.57100044583.9
other121.25090.551.37590.52.57140060794.8
12 x 1 5/8" *< 1/4"121.37572.551.50072.52.57110048693.2
other121.37590.551.50090.52.57140060865.4
12 x 1 3/4" *< 1/4"121.37578.551.62578.52.57120052778.4
other121.37596.551.62596.52.57150064957.0
12 x 1 7/8" *< 1/4"121.50084.551.75084.52.57130056903.8
other121.50096.551.75096.52.571500641032.2
12 x 2" *< 1/4"121.50090.551.75090.52.57140060968.0
other121.50096.551.75096.52.571500641032.2
12 x 2 1/8" *< 1/4"121.62596.551.87596.52.571500641107.5
12 x 2 1/4" *< 1/4"121.750102.551.875102.52.571600681219.9
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
13 x 3/4"< 1/4"130.62548.54.50.87548.53.256.570032250.4
other130.62578.54.50.87578.53.256.5120052405.6
13 x 7/8" *< 1/4"130.75048.550.75048.53770032267.6
other130.75072.550.87572.537110048425.9
13 x 1" *< 1/4"130.87554.550.87554.53780036345.2
other130.75078.551.00078.537120052489.0
13 x 1 1/8" *< 1/4"130.87554.551.12554.53780036383.9
other130.87584.551.12584.537130056595.3
13 x 1 1/4" *< 1/4"131.00060.551.25060.53790040475.5
other131.00090.551.25090.537140060711.4
13 x 1 3/8" *< 1/4"131.12566.551.37566.537100044576.9
other131.12590.551.37590.537140060785.2
13 x 1 1/2" *< 1/4"131.25072.551.50072.537110048688.1
other131.25096.551.50096.537150064915.9
13 x 1 5/8" *< 1/4"131.37578.551.62578.537120052809.0
other131.375102.551.625102.5371600681056.5
13 x 1 3/4" *< 1/4"131.50090.551.62590.537140060974.4
other131.500102.551.875102.5371600681176.4
13 x 1 7/8" *< 1/4"131.50096.551.62596.5371500641039.1
other131.500102.551.875102.5371600681176.4
13 x 2" *< 1/4"131.625102.551.750102.5371600681187.3
other131.625144.551.750144.5372300961673.9
13 x 2 1/8" *< 1/4"131.750102.552.125102.5371600681343.5
13 x 2 1/4" *< 1/4"131.750144.552.000144.5372300961842.9
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Staggered Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
14 x 3/4”< 1/4”140.62527.55.50.75027.525312.532163.0
other140.62545.55.50.75045.525612.556272.5
14 x 7/8” *< 1/4”140.75033.55.50.87533.525412.540229.2
other140.75039.55.50.87539.525512.548271.0
14 x 1” *< 1/4”140.87533.55.50.87533.525412.540245.8
other140.87545.55.51.00045.525612.556353.2
14 x 1 1/8” *< 1/4”141.00039.55.51.00039.525512.548325.6
other141.00051.55.51.00051.525712.564425.9
14 x 1 1/4” *< 1/4”141.00039.55.51.12539.525512.548341.0
other141.00051.55.51.12551.525712.564446.0
14 x 1 3/8” *< 1/4”141.12539.55.51.25039.525512.548376.0
other141.12557.55.51.25057.525812.572549.4
14 x 1 1/2” *< 1/4”141.25045.55.51.37545.525612.556474.1
other141.25057.55.51.37557.525812.572600.3
14 x 1 5/8” *< 1/4”141.37551.55.51.37551.525712.564562.8
other141.37563.55.51.37563.525912.580695.0
14 x 1 3/4” *< 1/4”141.50051.55.51.50051.525712.564608.4
other141.50063.55.51.50063.525912.580751.2
14 x 1 7/8” *< 1/4”141.62557.55.51.62557.525812.572730.8
other141.50063.55.51.75063.525912.580800.8
14 x 2” *< 1/4”141.62557.55.51.75057.525812.572753.2
other141.62563.55.51.75063.525912.580832.3
14 x 2 1/8” *< 1/4”141.75063.55.51.87563.525912.580888.5
14 x 2 1/4” *< 1/4”141.87569.55.51.87569.5251012.5881007.4
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Staggered Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
15 x 3/4”< 1/4”150.62533.56.50.62533.526412.540204.2
other150.62551.56.50.62551.526712.564316.4
15 x 7/8”< 1/4”150.62533.56.50.75033.526412.540219.7
other150.62551.56.50.75051.526712.564340.1
15 x 1” *< 1/4”150.75033.56.50.87533.526412.540252.9
other150.75045.56.50.87545.526612.556345.1
15 x 1 1/8” *< 1/4”150.87539.56.51.00039.526512.548338.2
other150.87551.56.51.00051.526712.564442.3
15 x 1 1/4” *< 1/4”151.00039.56.51.00039.526512.548359.2
other151.00057.56.51.00057.526812.572524.9
15 x 1 3/8” *< 1/4”151.12545.56.51.12545.526612.556459.6
other151.12557.56.51.12557.526812.572582.0
15 x 1 1/2” *< 1/4”151.25051.56.51.25051.526712.564571.9
other151.25063.56.51.25063.526912.580706.2
15 x 1 5/8” *< 1/4”151.25051.56.51.37551.526712.564595.7
other151.25063.56.51.37563.526912.580735.5
15 x 1 3/4” *< 1/4”151.37557.56.51.37557.526812.572696.1
other151.37563.56.51.37563.526912.580769.2
15 x 1 7/8” *< 1/4”151.50057.56.51.50057.526812.572753.2
other151.50069.56.51.50069.5261012.588911.3
15 x 2” *< 1/4”151.62563.56.51.62563.526912.580895.3
other151.62569.56.51.62569.5261012.588980.3
15 x 2 1/8” *< 1/4”151.62563.56.51.75063.526912.580924.5
15 x 2 1/4” *< 1/4”151.75069.56.51.75069.5261012.5881049.3
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
16 x 3/4”< 1/4”160.62530.570.62530.52641340200.2
other160.62548.570.62548.52671364318.7
16 x 7/8”< 1/4”160.62536.570.75036.52651348257.8
other160.62554.570.75054.52681372385.2
16 x 1” *< 1/4”160.75030.570.87530.52641340247.7
other160.75048.570.87548.52671364394.3
16 x 1 1/8” *< 1/4”160.87536.570.87536.52651348317.3
other160.87554.570.87554.52681372474.1
16 x 1 1/4” *< 1/4”161.00042.571.00042.52661356414.7
other161.00054.571.00054.52681372532.0
16 x 1 3/8” *< 1/4”161.00042.571.12542.52661356435.8
other161.00054.571.12554.52681372559.1
16 x 1 1/2” *< 1/4”161.12542.571.25042.52661356481.0
other161.12560.571.25060.52691380685.0
16 x 1 5/8” *< 1/4”161.25048.571.25048.52671364576.5
other161.25066.571.25066.526101388790.7
16 x 1 3/4” *< 1/4”161.37554.571.37554.52681372705.9
other161.37566.571.37566.526101388861.5
16 x 1 7/8” *< 1/4”161.50060.571.50060.52691380848.0
other161.50066.571.50066.526101388932.2
16 x 2” *< 1/4”161.50060.571.50060.52691380848.0
other161.50066.571.50066.526101388932.2
16 x 2 1/8” *< 1/4”161.62566.571.62566.5261013881002.9
16 x 2 1/4” *< 1/4”161.62566.571.75066.5261013881035.9
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
17 x 3/4"< 1/4”170.62530.570.75030.52.256.541340220.7
other170.62548.570.75048.52.256.571364351.3
17 x 7/8" *< 1/4”170.75030.570.75030.52741340239.1
other170.75048.570.75048.52771364380.6
17 x 1" *< 1/4”170.87536.570.87536.52751348326.3
other170.87548.571.00048.52771364457.9
17 x 1 1/8" *< 1/4”170.87536.571.00036.52751348344.5
other170.87554.571.00054.52781372514.6
17 x 1 1/4" *< 1/4”171.00042.571.00042.52761356426.8
other171.00054.571.12554.52781372574.5
17 x 1 3/8" *< 1/4”171.00042.571.25042.52761356469.0
other171.00060.571.25060.52791380667.9
17 x 1 1/2" *< 1/4”171.12548.571.37548.52771364588.6
other171.12560.571.37560.52791380734.3
17 x 1 5/8" *< 1/4”171.25054.571.37554.52781372694.3
other171.25066.571.37566.527101388847.3
17 x 1 3/4" *< 1/4”171.37560.571.37560.52791380807.3
other171.37572.571.3752.527111396967.5
17 x 1 7/8" *< 1/4”171.50066.571.50066.527101388960.5
other171.50072.571.50072.5271113961047.2
17 x 2" *< 1/4”171.50066.571.62566.527101388993.5
other171.50072.571.62572.5271113961083.1
17 x 2 1/8" *< 1/4”171.62566.571.75066.5271013881066.5
17 x 2 1/4" *< 1/4”171.75072.571.75072.5271113961206.5
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
18 x 3/4"< 1/4”180.62536.580.62536.52.256.5513.548265.5
other180.62554.580.62554.52.256.5813.572396.8
18 x 7/8" *< 1/4”180.75030.580.75030.52.5741340258.5
other180.75048.580.75048.52.5771364411.5
18 x 1" *< 1/4”180.75036.580.87536.52.5751348330.2
other180.75054.580.87554.52.5781372493.4
18 x 1 1/8" *< 1/4”180.87542.580.87542.52.5761356411.7
other180.87560.580.87560.52.5791380586.4
18 x 1 1/4" *< 1/4”181.00042.581.00042.52.5761356463.0
other181.00060.581.12560.52.5791380693.6
18 x 1 3/8" *< 1/4”181.00048.581.12548.52.5771364555.9
other181.00066.581.12566.52.57101388762.5
18 x 1 1/2" *< 1/4”181.12548.581.25048.52.5771364614.4
other181.12566.581.25066.52.57101388842.6
18 x 1 5/8" *< 1/4”181.25054.581.25054.52.5781372725.2
other181.25072.581.25072.52.57111396964.9
18 x 1 3/4" *< 1/4”181.37560.581.37560.52.5791380878.0
other181.37572.581.37572.52.571113961052.3
18 x 1 7/8" *< 1/4”181.37560.581.50060.52.5791380912.3
other181.37572.581.50072.52.571113961093.4
18 x 2" *< 1/4”181.50066.581.62566.52.571013881083.0
other181.50072.581.62572.52.571113961180.8
18 x 2 1/8" *< 1/4”181.62572.581.62572.52.571113961227.1
18 x 2 1/4" *< 1/4”181.75078.581.75078.52.5712131041423.3
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
19 x 7/8" *< 1/4”190.75036.58.50.75036.52.57513.548325.1
other190.75054.58.50.75054.52.57813.572485.7
19 x 1" *< 1/4”190.75036.58.50.87536.52.57513.548347.0
other190.75054.58.50.87554.52.57813.572518.5
19 x 1 1/8" *< 1/4”190.87542.58.50.87542.52.57613.556432.8
other190.87560.58.50.87560.52.57913.580616.4
19 x 1 1/4" *< 1/4”191.00048.58.51.00048.52.57713.564555.9
other191.00066.58.51.00066.52.571013.588762.5
19 x 1 3/8" *< 1/4”191.00048.58.51.12548.52.57713.564585.1
other191.00066.58.51.12566.52.571013.588802.5
19 x 1 1/2" *< 1/4”191.12554.58.51.25054.52.57813.572727.1
other191.12572.58.51.25072.52.571113.596967.5
19 x 1 5/8" *< 1/4”191.25060.58.51.25060.52.57913.580848.0
other191.25078.58.51.25078.52.571213.51041100.5
19 x 1 3/4" *< 1/4”191.37566.58.51.37566.52.571013.5881017.0
other191.37578.58.51.37578.52.571213.51041200.7
19 x 1 7/8" *< 1/4”191.37566.58.51.50066.52.571013.5881057.1
other191.37578.58.51.50078.52.571213.51041248.0
19 x 2" *< 1/4”191.50066.58.51.62566.52.571013.5881142.0
other191.50078.58.51.62578.52.571213.51041348.1
19 x 2 1/8" *< 1/4”191.62578.58.51.62578.52.571213.51041401.0
19 x 2 1/4" *< 1/4”191.75084.58.51.75084.52.571313.51121616.0
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
20 x 7/8" *< 1/4”200.75036.590.75036.52.5751448340.6
other200.75054.590.75054.52.5781472508.8
20 x 1" *< 1/4”200.75036.590.87536.52.5751448363.9
other200.75060.590.87560.52.5791480603.5
20 x 1 1/8" *< 1/4”200.87542.590.87542.52.5761456453.9
other200.87566.590.87566.52.57101488710.6
20 x 1 1/4" *< 1/4”201.00048.591.00048.52.5771464583.4
other201.00072.591.00072.52.57111496872.4
20 x 1 3/8" *< 1/4”201.00054.591.12554.52.5781472690.4
other201.00072.591.12572.52.57111496918.7
20 x 1 1/2" *< 1/4”201.12554.591.25054.52.5781472763.8
other201.12572.591.25072.52.571114961016.3
20 x 1 5/8" *< 1/4”201.25060.591.25060.52.5791480890.9
other201.25078.591.25078.52.5712141041156.1
20 x 1 3/4" *< 1/4”201.37566.591.37566.52.571014881068.9
other201.37584.591.37584.52.5713141121358.4
20 x 1 7/8" *< 1/4”201.37566.591.50066.52.571014881111.3
other201.37578.591.50078.52.5712141041312.0
20 x 2" *< 1/4”201.50072.591.62572.52.571114961309.3
other201.50078.591.62578.52.5712141041417.7
20 x 2 1/8" *< 1/4”201.62578.591.62578.52.5712141041473.3
20 x 2 1/4" *< 1/4”201.75084.591.75084.52.5713141121699.8
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
21 x 7/8" *< 1/4”210.75036.59.50.75036.52.57514.548356.1
other210.75060.59.50.75060.52.57914.580590.7
21 x 1" *< 1/4”210.75042.59.50.87542.52.57614.556443.4
other210.75060.59.50.87560.52.57914.580631.4
21 x 1 1/8" *< 1/4”210.87548.59.50.87548.52.57714.564542.2
other210.87566.59.50.87566.52.571014.588743.6
21 x 1 1/4" *< 1/4”211.00054.59.51.00054.52.57814.572686.6
other211.00072.59.51.00072.52.571114.596913.5
21 x 1 3/8" *< 1/4”211.00054.59.51.12554.52.57814.572723.3
other211.00072.59.51.12572.52.571114.596962.4
21 x 1 1/2" *< 1/4”211.12560.59.51.25060.52.57914.580888.7
other211.12578.59.51.25078.52.571214.51041153.4
21 x 1 5/8" *< 1/4”211.25066.59.51.25066.52.571014.5881026.5
other211.25084.59.51.25084.52.571314.51121304.5
21 x 1 3/4" *< 1/4”211.37572.59.51.37572.52.571114.5961221.9
other211.37584.59.51.37584.52.571314.51121424.3
21 x 1 7/8" *< 1/4”211.37572.59.51.50072.52.571114.5961270.7
other211.37584.59.51.50084.52.571314.51121481.2
21 x 2" *< 1/4”211.50078.59.51.62578.52.571214.51041487.3
other211.50084.59.51.62584.52.571314.51121601.0
21 x 2 1/8" *< 1/4”211.62584.59.51.62584.52.571314.51121663.9
21 x 2 1/4" *< 1/4”211.75090.59.51.75090.52.571414.51201910.4
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
22 x 1" *< 1/4”220.75030.5100.87530.52642360351.1
other220.75042.5100.87542.52662384489.6
22 x 1 1/8" *< 1/4”220.87530.5100.87530.52642360374.8
other220.87548.5100.87548.52672396596.6
22 x 1 1/4" *< 1/4”221.00036.5101.00036.52652372503.1
other221.00048.5101.00048.52672396668.8
22 x 1 3/8" *< 1/4”221.00036.5101.12536.52652372529.0
other221.00048.5101.12548.52672396703.2
22 x 1 1/2" *< 1/4”221.12542.5101.25042.52662384679.4
other221.12554.5101.25054.526823108871.5
22 x 1 5/8" *< 1/4”221.25042.5101.25042.52662384712.5
other221.25054.5101.25054.526823108913.9
22 x 1 3/4" *< 1/4”221.25048.5101.37548.52672396847.6
other221.25054.5101.37554.526823108952.6
22 x 1 7/8" *< 1/4”221.37548.5101.50048.52672396919.8
other221.37560.5101.50060.5269231201147.6
22 x 2" *< 1/4”221.50054.5101.62554.5268231081114.9
other221.50060.5101.62560.5269231201237.7
22 x 2 1/8" *< 1/4”221.50054.5101.62554.5268231081114.9
22 x 2 1/4" *< 1/4”221.62560.5101.75060.5269231201327.8
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
23 x 1" *< 1/4”230.75030.510.50.87530.52.256.542360365.1
other230.75042.510.50.87542.52.256.562384509.1
23 x 1 1/8" *< 1/4”230.87530.510.50.87530.52.256.542360390.0
other230.87548.510.50.87548.52.256.572396620.7
23 x 1 1/4" *< 1/4”231.00036.510.51.00036.52.256.552372523.8
other231.00048.510.51.00048.52.256.572396696.3
23 x 1 3/8" *< 1/4”231.00042.510.51.12542.52.256.562384641.7
other231.00054.510.51.12554.52.256.5823108823.2
23 x 1 1/2" *< 1/4”231.12542.510.51.25042.52.256.562384708.0
other231.12554.510.51.25054.52.256.5823108908.2
23 x 1 5/8" *< 1/4”231.25048.510.51.25048.52.256.572396847.6
other231.25060.510.51.25060.52.256.59231201057.6
23 x 1 3/4" *< 1/4”231.25048.510.51.37548.52.256.572396883.7
other231.25060.510.51.37560.52.256.59231201102.6
23 x 1 7/8" *< 1/4”231.37554.510.51.50054.52.256.58231081078.2
other231.37560.510.51.50060.52.256.59231201197.0
23 x 2" *< 1/4”231.50054.510.51.62554.52.256.58231081163.2
other231.50060.510.51.62560.52.256.59231201291.3
23 x 2 1/8" *< 1/4”231.50060.510.51.62560.52.256.59231201291.3
23 x 2 1/4" *< 1/4”231.62560.510.51.75060.52.256.59231201385.7
* Bolt threads are EXCLUDED from shear plane
Flange Filler
Plate
Thick.
Outer Plate Inner Plates Uniform Bolt Pattern WT./FLG.
with 7/8"
Bolts (lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J
(in)
K
(in)
L
(in)
Total #
of Bolts
24 x 1" *< 1/4”240.75030.5110.87530.52.5742360379.2
other240.75048.5110.87548.52.5772396603.5
24 x 1 1/8" *< 1/4”240.87536.5110.87536.52.5752372485.0
other240.87548.5110.87548.52.5772396644.8
24 x 1 1/4" *< 1/4”241.00036.5111.00036.52.5752372544.5
other241.00054.5111.00054.52.57823108813.5
24 x 1 3/8" *< 1/4”241.00042.5111.12542.52.5762384667.3
other241.00054.5111.12554.52.57823108856.0
24 x 1 1/2" *< 1/4”241.12542.5111.25042.52.5762384736.6
other241.12560.5111.25060.52.579231201049.0
24 x 1 5/8" *< 1/4”241.25048.5111.25048.52.5772396882.0
other241.25060.5111.25060.52.579231201100.5
24 x 1 3/4" *< 1/4”241.25048.5111.37548.52.5772396919.8
other241.25060.5111.37560.52.579231201147.6
24 x 1 7/8" *< 1/4”241.37554.5111.50054.52.578231081122.6
other241.37560.5111.50060.52.579231201246.3
24 x 2" *< 1/4”241.50060.5111.62560.52.579231201344.9
other241.50066.5111.62566.52.5710231321478.4
24 x 2 1/8" *< 1/4”241.50060.5111.62560.52.579231201344.9
24 x 2 1/4" *< 1/4”241.62566.5111.75066.52.5710231321586.8
* Bolt threads are EXCLUDED from shear plane

751.14.3.3 Plate Girder - Web Splice Tables

Web Plate Depth: 36" thru 96" (4 or 6 rows of Bolts), ASTM A709, Grade 50 and 50W Webs, Grade 50 and 50W Splices


Image:751.14 WEB PLATE DEPTH 36in thru 96in (4 or 6 rows of Bolts).gif
Note:Provide shim plates when connecting webs that differ in thickness by 1/8” or more. Use an equal number of shim plates on each side of the web. Uniformity of web plate thicknesses, which would eliminate the need for the minimum thickness of shim plate, should also be considered.


Web Dimensions Splice Plates Bolts WT./Splice
with 7/8"
Bolts (lb)
Web
Depth
(in)
Web
Thickness (in)
Plate
Width
a (in)
Plate
Depth
b (in)
# of
rows
(m)
# of
bolts per
row (n)
Spacing
pitch (s) (in) gage (g) (in) center (c) (in) clearance (e) (in)
363/81431293.5354126.5
7/1613.533211334.53136.5
383/81435294353138.4
7/161434.52103.5353.25140.7
403/81435294354138.4
7/1613.536212334.53.5149.0
1/219.53539434.54196.4
423/813.5382113.534.53.5150.9
7/1613.5382113.534.53.5150.9
1/213.539213334.53161.4
443/81439294.5354150.3
7/1614382113.5354.5154.9
1/213.539213334.54161.4
463/81443295353162.2
7/1613.543211434.53165.3
1/213.542214334.53.5173.8
9/1619433114343236.5
483/81443295354162.2
7/1614432114354169.8
1/213.5452133.534.53178.6
9/1619433114344236.5
Web Dimensions Splice Plates Bolts WT./Splice
with 7/8"
Bolts (lb)
Web
Depth
(in)
Web
Thickness (in)
Plate
Width
a (in)
Plate
Depth
b (in)
# of
rows
(m)
# of
bolts per
row (n)
Spacing
pitch (s) (in) gage (g) (in) center (c) (in) clearance (e) (in)
503/81443.52104.5354.75167.5
7/1613.547212434.53180.5
1/213.545215334.54186.2
9/1619473124343258.3
523/814482105353.5180.9
7/1614482114.5353.5184.7
1/213.548.52143.534.53.25192.4
9/1613482163343.5193.5
5/81948.53143.5343.25275.8
547/1613.551213434.53195.8
1/213.551213434.53195.8
9/1613512173343205.6
5/819513134343280.2
567/1614532115353199.6
1/213.5522153.534.53.5206.3
9/1613512173344205.6
5/819523153.5343.5295.6
587/161452.52124.5354.25201.9
1/213.5522153.534.54.5206.3
9/1613542183343.5217.7
5/819553144343302.0
Web Dimensions Splice Plates Bolts WT./Splice
with 7/8"
Bolts (lb)
Web
Depth
(in)
Web
Thickness (in)
Plate
Width
a (in)
Plate
Depth
b (in)
# of
rows
(m)
# of
bolts per
row (n)
Spacing
pitch (s) (in) gage (g) (in) center (c) (in) clearance (e) (in)
607/1613.5572134.534.53213.1
1/213.555.52163.534.53.75220.1
9/1613542183344.5217.7
5/819573134.5343304.4
627/1614572134.5354219.1
1/213.559215434.53226.4
9/1613592173.5343227.7
5/819593154343323.9
11/1619593173.5343335.3
647/1613.559215434.54226.4
1/213.5592173.534.54234.0
9/1613572193345229.8
5/819593154344323.9
11/1619593173.5344335.3
661/213.563216434.53241.7
9/161362.52183.5343.25241.2
5/813632213343254.0
11/1619633164343345.8
681/213.563216434.54241.7
9/1613632213344254.0
5/819633164344345.8
11/161962.53183.5344.25355.1
701/213.567217434.53257.0
9/1613662193.5343.5254.7
5/813662223343.5266.1
11/1619673174343367.6
721/213.567217434.54257.0
9/1613662223344.5266.1
5/813692233343278.2
11/1619673174344367.6
741/213.571218434.53272.2
9/161369.52203.5343.75268.2
5/813692233344278.2
11/1619713184343389.5
769/1613732213.5343281.6
5/813722243343.5290.3
11/1619713184344389.5
789/1613732213.5344281.6
5/813722243344.5290.3
11/1619753174.5343400.0
809/161376.52223.5343.25295.1
5/813752253344302.4
11/1619753194344411.4
829/161376.52223.5344.25295.1
5/813752253345302.4
11/1619793204343433.2
849/1613802233.5343.5308.6
5/813782263344.5314.5
11/1613812273343326.5
865/813812273344326.5
11/1619793204345433.2
885/813812273345326.5
11/1613842283343.5338.6
905/813872253.5343335.5
11/1613872293343350.7
925/813842283345.5338.6
11/161988.53204.5343.25471.6
945/81390.52263.5343.25349.0
11/1613902303343.5362.8
965/813902303344.5362.8
11/1613932313.5343374.9

751.14.3.4 Wide Flange Splice Tables

27” Wide Flange Beams

ASTM A709, Grade 50 and 50W Webs, Grade 50 and 50W Splices


Image:751.14 27in wide flange splice.gif


Note:Bottom flange splice plates are the same as the top. Provide shim plates when connecting webs that differ in thickness by 1/8” or more. Use an equal number of shim plates on each side of the web. Use the smallest beam size to determine splice details.


Size of
Beam
Filler
Plate
Thick.
Outer Plate Inner Plates Web Splice Plates Total
Number
of Bolts
Weight
(lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
J a
(in)
b
(in)
c
(in)
m
W27x84**< 1/4"100.37518.53.50.518.5219.521.750.4375360238.3
other100.37524.53.50.524.5319.521.750.4375368270.6
W27x94**< 1/4"100.524.53.50.62524.5325.521.750.5480363.5
other100.530.53.50.62530.5425.521.750.5488403.0
W27x102**< 1/4"100.524.53.50.62524.5325.521.750.5625480383.2
other----------------------------------------- Design by Hand ------------------------------------------
W27x114**< 1/4"100.524.53.50.7524.5325.521.750.5625480395.4
other----------------------------------------- Design by Hand ------------------------------------------
W27x129**< 1/4"100.562530.53.50.87530.5431.521.750.68755100565.4
other----------------------------------------- Design by Hand ------------------------------------------
** Denotes flange widths less than 12” where P/S Panel placement should be thoroughly investigated.



30” Wide Flange Beams

ASTM A709, Grade 50 and 50W Webs, Grade 50 and 50W Splices


Image:751.14 30in wide flange splice.gif


Note:Bottom flange splice plates are the same as the top. Provide shim plates when connecting webs that differ in thickness by 1/8” or more. Use an equal number of shim plates on each side of the web. Use the smallest beam size to determine splice details.


Size of
Beam
Filler
Plate
Thick.
Outer Plate Inner Plates Web Splice Plates Total
Number
of Bolts
Weight
(lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
J a
(in)
b
(in)
c
(in)
m
W30x90**< 1/4"10.50.37518.53.50.518.5219.5240.4375372262.6
other10.50.37530.53.50.530.5419.5240.4375388328.4
W30x99**< 1/4"10.50.37524.53.50.524.5319.5240.5380312.0
other10.50.37530.53.50.530.5419.5240.5388345.0
W30x108**< 1/4"10.50.524.53.50.62524.5319.5240.5380342.4
other10.50.536.53.50.62536.5519.5240.5396423.1
W30x116**< 1/4"10.50.530.53.50.7530.5425.5240.56254104475.7
other10.50.530.53.50.7530.5425.5240.56254104475.7
W30x124**< 1/4"10.50.530.53.50.7530.5425.5240.56254104475.7
other10.50.530.53.50.7530.5425.5240.56254104475.7
W30x132**< 1/4"10.50.530.53.50.7530.5425.5240.6254104497.4
other----------------------------------------- Design by Hand ------------------------------------------
W30x148**< 1/4"10.50.62536.53.50.87536.5525.5240.6254112586.0
other----------------------------------------- Design by Hand ------------------------------------------
** Denotes flange widths less than 12” where P/S Panel placement should be thoroughly investigated.


33” Wide Flange Beams

ASTM A709, Grade 50 and 50W Webs, Grade 50 and 50W Splices


Image:751.14 33in wide flange splice a.gif


Note:Bottom flange splice plates are the same as the top. Provide shim plates when connecting webs that differ in thickness by 1/8” or more. Use an equal number of shim plates on each side of the web. Use the smallest beam size to determine splice details.


Size of
Beam
Filler
Plate
Thick.
Outer Plate Inner Plates Web Splice Plates Total
Number
of Bolts
Weight
(lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
J a
(in)
b
(in)
c
(in)
m
W33x118**< 1/4"11.50.530.53.50.62530.5419.5270.5394413.7
other11.50.536.53.50.62536.5519.5270.53102455.8
W33x130**< 1/4"11.50.530.53.50.7530.5425.5270.56254112516.3
other11.50.542.53.50.7542.5625.5270.56254128606.4
W33x141**< 1/4"11.50.62536.53.50.87536.5525.5270.56254120609.2
other11.50.62542.53.50.87542.5625.5270.56254128662.1
W33x152**< 1/4"11.50.62536.53.50.87536.5525.5270.6254120633.6
other----------------------------------------- Design by Hand ------------------------------------------
W33x169**< 1/4"11.50.62536.53.5136.5525.5270.6254120651.7
other----------------------------------------- Design by Hand ------------------------------------------
** Denotes flange widths less than 12” where P/S Panel placement should be thoroughly investigated.


33” Wide Flange Beams

ASTM A709, Grade 50 and 50W Webs, Grade 50 and 50W Splices


Image:751.14 33in wide flange splice b.gif


Note:Bottom flange splice plates are the same as the top. Provide shim plates when connecting webs that differ in thickness by 1/8” or more. Use an equal number of shim plates on each side of the web. Use the smallest beam size to determine splice details.


Size of
Beam
Filler
Plate
Thick.
Outer Plate Inner Plates Web Splice Plates Total
Number
of Bolts
Weight
(lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J a
(in)
b
(in)
c
(in)
m
W33x201< 1/4"15.750.62524.560.87524.525.75324.5270.68754136669.8
other------------------------------------------------------- Design by Hand --------------------------------------------------------
W33x221< 1/4"15.750.7530.560.87530.525.75430.5270.755170897.7
other------------------------------------------------------- Design by Hand --------------------------------------------------------


36” Wide Flange Beams

ASTM A709, Grade 50 and 50W Webs, Grade 50 and 50W Splices


Image:751.14 36in wide flange splice.gif


Note:Bottom flange splice plates are the same as the top. Provide shim plates when connecting webs that differ in thickness by 1/8” or more. Use an equal number of shim plates on each side of the web. Use the smallest beam size to determine splice details.


Size of
Beam
Filler
Plate
Thick.
Outer Plate Inner Plates Web Splice Plates Total
Number
of Bolts
Weight
(lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
J a
(in)
b
(in)
c
(in)
m
W36x135< 1/4"120.62530.540.62530.5419.5300.53100477.1
other120.62542.540.62542.5619.5300.53116577.4
W36x150< 1/4"120.62536.540.7536.5525.5300.56254128645.1
other120.62542.540.7542.5625.5300.56254136698.6
W36x160< 1/4"120.62536.540.87536.5525.5300.56254128665.8
other----------------------------------------- Design by Hand ------------------------------------------
W36x170< 1/4"120.62536.540.87536.5525.5300.56254128665.8
other----------------------------------------- Design by Hand ------------------------------------------
W36x182< 1/4"120.7542.54142.5625.5300.6254136810.1
other----------------------------------------- Design by Hand ------------------------------------------
W36x194< 1/4"120.7542.54142.5625.5300.6254136810.1
other----------------------------------------- Design by Hand ------------------------------------------


40” Wide Flange Beams

ASTM A709, Grade 50 and 50W Webs, Grade 50 and 50W Splices


Image:751.14 40in wide flange splice.gif


Note:Bottom flange splice plates are the same as the top. Provide shim plates when connecting webs that differ in thickness by 1/8” or more. Use an equal number of shim plates on each side of the web. Use the smallest beam size to determine splice details.


Size of
Beam
Filler
Plate
Thick.
Outer Plate Inner Plates Web Splice Plates Total
Number
of Bolts
Weight
(lb)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
I
(in)
J a
(in)
b
(in)
c
(in)
m
W40x149**< 1/4"11.750.62530.53.50.7530.52.6256.5419.5330.43753106478.2
other11.750.62542.53.50.7542.52.6256.5619.5330.43753122579.1
W40x167**< 1/4"11.750.7536.53.5136.52.56.75525.5330.54136695.1
other11.750.7548.53.5148.52.56.75725.5330.54152818.0
W40x183**< 1/4"11.750.7542.53.51.12542.52.56.75625.5330.54144777.6
other11.750.7542.53.51.12542.52.56.75625.5330.54144777.6
W40x199***< 1/4"15.750.62524.55.750.7524.526.25325.5330.54152639.6
other------------------------------------------------------- Design by Hand --------------------------------------------------------
W40x211**< 1/4"11.750.7548.53.51.2548.52.56.75725.5330.6254152925.7
other------------------------------------------------------- Design by Hand --------------------------------------------------------
W40x215***< 1/4"15.750.62530.55.750.87530.526.25425.5330.56254168772.4
other------------------------------------------------------- Design by Hand --------------------------------------------------------
** Denotes flange widths less than 12” where P/S Panel placement should be thoroughly investigated.
*** Outer splice plates with widths of 15 3/4” have 4 rows of flange bolts in lieu of 2 rows per drawing.

751.14.3.5 Shop Welded Splices

Reference: LRFD Figure 6.13.6.2-1


The following details and note shall be provided on all plate girder bridges.
Image:751.14 welded shop web splice.gif
Welded Shop web Splice  
 
Image:751.14 welded shop splice plan.gif
Plan  
2'-0" Radius Transition  
 
Image:751.14 welded shop splice section a-a.gif
Section A-A  
Welded Shop Flange Splice  
Note:Welded shop web and flange splices may be permitted when detailed on the shop drawings and approved by the engineer. No additional payment will be made for optional welded shop web and flange splices.


Image:751.14 welded shop splice.gif
Welded Shop Splice
Notes:See Structural Project Manager before utilizing this detail.
 It is recommended to avoid this detail if possible.

751.14.4 Composite Design

751.14.4.1 General

Overview

The pitch of shear connectors shall be determined to satisfy the fatigue limit state, and the resulting number of shear connectors shall not be less than the number required to satisfy the strength limit state.

Cross-section properties are based on the transformed short-term composite section. Cross-section properties of the composite section shall include concrete slab and steel section. Longitudinal deck reinforcement shall not be considered to be a part of the composite section. Cross-section properties of the non-composite section shall include the steel section only. Negative flexure regions in horizontally curved girders may include the steel reinforcement in the composite section.

The stresses of composite girders and slab shall be computed using the composite cross-section properties and shall be consistent with the properties of the various materials used. The ratio of modulus of elasticity of steel to that of concrete, \, n, shall be taken to be 8 when using deck concrete with \, f'_c = 4 KSI.

The effective flange widths for calculating composite sections for interior and exterior girders should be determined by LRFD 4.6.2.6 prior to beginning shear connector design. In order to have a uniform and conservative shear connector design for all girders, the smaller effective flange width, between the interior and exterior girders, should only be used to locate the acceptable areas for placement of additional connectors near point of dead load contraflexure. The larger effective flange width should be used in all other calculations.

An effective slab thickness shall be used for composite design by deducting from the actual slab thickness a 1” integral, sacrificial wearing surface.

New Bridges or Replacement of Existing Superstructures

The regions of the bridge subjected to positive flexure are to be designed as composite and the regions subjected to negative flexure are to be designed as non-composite. Simple span composite bridges shall be provided with shear connectors throughout the length of the span. Continuous composite bridges are to be designed with shear connectors provided in the positive flexure regions only, with additional connectors required in the regions of permanent load contraflexure. Horizontally curved girders require shear connectors throughout the girder length.

For the initial girder design, composite/noncomposite regions can be approximately assumed as:

Redeckings

If existing bridge is partially composite, then leave as partially composite unless making full-length composite will reduce or eliminate a load posting subject to Structural Project Manager or Structural Liaison Engineer approval. If the existing bridge is not composite, then make it full-length composite since this will give the maximum capacity of the bridge for the next service life cycle. This guidance applies to either LRFD or LFD redecking designs. Shear connector design should follow same design code used for redecking.

Design Loading

The girder shear force range due to fatigue loading, \, V_{SR}, should be determined from structural analysis prior to beginning shear connector design. The shear force range is the difference in the minimum and maximum shear force envelopes at any point. For design, use the average shear force range over the effective span (i.e. between contraflexure points). For horizontally curved girders the lateral component of the fatigue force range should be considered.

The stress range in the longitudinal reinforcement due to fatigue loading, \, f_{sr}, should be determined prior to beginning shear stud design. In lieu of more accurate computation, \, f_{sr} may be assumed to be 10 ksi.

  • Note: This assumption is not provided by AASHTO LRFD, but is held over from AASHTO LFD Specifications.


Other Considerations

Shear connectors shall not be placed on the flange splice plates. Maintain at least 3” from end of splice plate to nearest connector for fabrication purposes.

The effect of the shear connector on the fatigue resistance of the flange shall be investigated using the provisions of LRFD 6.6.1.2.

Note: All spacing dimensions are measured to center of shear connector

751.14.4.2 Shear Connector Limits

Shear Connector Proportions

Shear connector height, \, h_s, shall satisfy the following cover and deck penetration provisions:


Minimum shear connector penetration into deck:

  • For cast in place deck: 2 in.
  • For prestressed panel option: minimum penetration to top of panel


Minimum concrete clear cover over shear connectors = 3 in.


Choose a shear connector height that is acceptable for both SIP and CIP deck options. Use 1 in. increments for selecting shear connector height. Minimum shear connector height = 4 in.


Shear connector diameter, \, d, shall satisfy:

\, \frac {h_s}{d} \ge 4

Recommended shear connector diameters, \, d:

  • 3/4 in.
  • 7/8 in.


Shear Connector Configuration

The following transverse spacing provisions must be satisfied when determining the number of shear connectors per row, \, n:


Minimum transverse shear connector spacing:

  • Preferred minimum: 4d
  • Absolute minimum: 2 1/4 in.


Minimum distance between edge of top flange and nearest shear connector:

  • For cast in place deck: 1 1/2 in.
  • For prestressed panel option: 4 1/4 in.


Shear connectors shall be placed by units. A shear connector unit refers to all shear connectors in a given cross-section, spaced transversely across the top flange. Multiple shear connectors per unit may be used if spacing and clearances allow. For horizontally curved girders, when practical, a consistent unit layout and pitch shall be used throughout the span.

Shear Connector Spacing

If it becomes impractical to place the number of shear connectors required by ultimate strength in the specified distance (structures with span ratios greater than 1.5); base the number and spacing of shear connectors on the fatigue analysis only.

For a typical 3-span bridge, the shear connector units can be approximately arranged as below:

751.14.4.3 Fatigue Design

Fatigue Resistance

The number of fatigue cycles for design, N, shall be determined as:

\, N = (365)(75)(n_c)(ADTT_{SL})

Where:

\, n_c= number of stress range cycles per truck passage
\, ADTT_{SL}= single lane average daily truck traffic


For longitudinal members not near interior supports*:

\, n_c= 2.0 for spans ≤ 40 ft.
\, n_c= 1.0 for spans > 40 ft.
  • See LRFD Table 6.6.1.2.5-2 for other situations.


In absence of better information, the single lane average daily truck traffic shall be taken as:

\, ADTT_{SL} = (p_{tr})(ADTT)

Where:

ADTT= number of trucks per day in one direction, averaged over the design life
\, p_{tr} = fraction of truck traffic in a single lane


Number of Lanes
Available to Trucks
\, p_{tr}
11.00
20.85
3 or more0.80


The shear fatigue resistance of an individual shear connector, \, Z_r, is determined as follows:

\, Z_r = \alpha d^2 \ge \frac {5.5d^2}{2}

Where:

\, \alpha= shear fatigue factor
 = 34.5 – 4.28Log(N)


Pitch

Straight Girders

The maximum pitch of shear connectors along the longitudinal axis required to satisfy the fatigue limit state, \, p_{fat}, is determined as:

\, p_{fat} \le \frac {n Z_r I}{V_f Q}

Where:

\, n= number of shear connectors per unit
\, I= moment of inertia of the short-term composite section
\, V_f= vertical shear force range due to fatigue loading
\, Q= first moment of the transformed area of the slab about the neutral axis of the short-term composite section

Maximum pitch = 24 in.

Preferred minimum pitch = 6 in.

Absolute minimum pitch = 6d

Use 1 in. increments for pitch.


Horizontally Curved Girders (see Analysis of Horizontally Curved Girders)

Horizontally curved girders will receive a lateral fatigue component introduced by the diaphragms. The above equation for pitch shall be modified as follows:

\, p_{fat} \le \frac{n Z_r}{V_{sr}}

Where \, V_{sr} includes the longitudinal \, (V_{fat}) and radial \, (F_{fat}) fatigue shear ranges:

\, V_{sr} = \sqrt{(V_{fat})^2 + (F_{fat})^2}

\, V_{fat} = \frac{V_f Q}{I}


For bridge skews \, \le 20^\circ

\, F_{fat} \approx 0


For birdge skews \, > 20^\circ

\, F_{fat} = MAX \Bigg[ \frac{A_{bot} \sigma_{flg} l}{wR}, \frac{F_{rc}}{w} \Bigg]


Where:

\, A_{bot}= area of bottom flange
\, \sigma_{flg}= range of longitudinal fatigue stress range in bottom flange
\, l= distance between brace points
\, w= effective length of deck, 24” – end supports, 48” elsewhere
\, R= radius of girder; use minimum if radius transitions inside girder panel
\, F_{rc}= net range of diaphragm force at the top flange.

Note: For the purpose of the above calculations the bridge skew shall be taken as the maximum bent skew along the length of the bridge.

751.14.4.4 Strength Design

Resistance

The total nominal horizontal shear force between the point of maximum positive moment and each adjacent point of zero moment, Vh, is determined as:

\, P_p = MIN \begin{cases}
 0.85 f'_c bt_s \\
 F_{yw} Dt_w + F_{yt} b_t t_t + F_{yc} b_f t_f
\end{cases}\Bigg\}

Where:

\, f'_c= 28 day compressive strength of deck concrete
\, b= effective flange width
\, t_s= effective slab thickness
\, F_{yw}= yield strength of web
\, D= web depth
\, t_w= web thickness
\, F_{yt}= yield strength of tension flange
\, b_t= width of tension flange
\, t_t= thickness of tension flange
\, F_{yc}= yield strength of compression flange
\, b_f= width of compression flange
\, t_f= thickness of compression flange


The nominal shear resistance of a single shear connector embedded in a concrete slab, \, Q_n, is calculated as follows:

\, Q_n = 0.5 A_{SC} \sqrt{f'_c E_c} \le A_{sc} F_u

Where:

\, A_{sc}= cross sectional area of a shear connector
\, E_c= modulus of elasticity of deck concrete
\, F_u= tensile strength of shear connector steel


The factored resistance of a single shear connector, \, Q_r, shall be determined as:

\, Q_r = \phi_{sc} Q_n

Where

\, \phi_{sc}= resistance factor for shear connectors = 0.85


Calculated Resistance of Single Shear Connector
\, Q_r – Factored Resistance of One Shear Connector
\, (deck f'_c \ge 4 ksi)
Stud Diameter\, Q_r (k)
3/4"22.5
7/8"30.7


The minimum number of shear connectors required for strength in each region, \, n_{str}, shall be computed:

\, n_{str} = \frac {P_p}{Q_r}

Regions are defined as the areas between points of zero moment and adjacent points of maximum positive moment. \, n_{str} is the minimum number of shear connectors that must be placed in each region to satisfy the strength limit state.


Additional Connectors

The number of additional connectors to be placed in the region of permanent load contraflexure, \, n_{AC}, shall be:

n_{AC} = \frac {A_r f_{sr}}{Z_r}

Where:

\, A_r= total area of deck reinforcement within the effective flange width
\, f_{sr}= stress range in the longitudinal reinforcement due to fatigue loading


Minimum number of additional connectors = 4 units at 6d.

The additional shear connectors shall be placed within a distance of 1/3 of the minimum effective flange width on each side of the point of permanent load contraflexure.

If it is not possible to place additional connectors within b/3 from the point of dead load contraflexure, the additional connectors shall be placed as close to the contraflexure point as practical, using the minimum pitch of 6d.


Horizontally Curved Girders

Girders that are analyzed for curvature effects require shear connectors to be placed throughout the bridge. The provision for additional shear connector placement does not apply. Horizontally curved girders require separate analyses for regions near the end of the bridge and regions near interior supports. They also require a lateral shear force to be considered as shown below.

End of Bridge - Region:

\, P = \sqrt{{P_p}^2 + {F_p}^2}

Where:

\, F_p\, = P_p \frac{L_p}{R}= lateral shear force
\,L_p= arc length between end of girder and location of maximum positive moment
\, R= minimum radius over arc length, \, L_p.


Near interior support – Region

\, P = \sqrt{{P_T}^2 + {F_T}^2}

Where:

\, P_T = MIN \begin{cases}
 0.45 f'_c bt_s \\
 F_{yw} Dt_w + F_{yt} b_t t_t + F_{yc} b_f t_f
\end{cases}\Bigg\} for section over pier
\, F_T\, = P_T \frac{L_n}{R}= lateral shear force near an interior support  
\, L_n= arc length between point of maximum positive moment and interior support
\, R= minimum girder radius over length, \, L_n.

751.14.4.5 Shear Connector Details

Image:751.14 plan of shear connector unit.gif Image:751.14 circled 1.gif 6" cts. preferred min., 6d cts. absolute min., 24" cts. maximum. (1" increments min.)
Image:751.14 circled 2.gif = 2" minimum for CIP slab;
Image:751.14 circled 2.gif = a minimum height equal to the top of panel for P/S panel option.
Image:751.14 circled 3.gif 3" min. clear depth of concrete cover over shear connectors.
Plan Image:751.14 circled 4.gif 1 1/2" (Min.) CIP slab (*)
4 1/4" (Min.) panel option (*)
Image:751.14 section thru stringer or girder with and without cover plate.gif Image:751.14 circled 5.gif 4 x (Stud diameter) preferred minimum, may be reduced if necessary for a more economical design; 2 1/4" absolute minimum.
(*) Dimensions are not for detailing purposes.
(**) Requires the same dimension throughout the span.
"D""H"
3/4"1 1/4"
7/8"1 3/8"
Image:751.14 detail of shear connector.gif
Section Thru
Stringer or Girder
Section Thru
Cover Plate
 


Min Flange Width For
Given Rows of Studs (in.) (***)
Weight in Place
Per 100 Studs (lbs)
# of Studs
per unit, n
Absolute
Min.
Preferred Min. Stud Dia. 4" 5" 6" 7"
3/4" dia. 7/8" dia. 3/4" 63 75 88 100
2 10.75 11.50 12.00
3 13.00 14.50 15.50 7/8" 81 98 115 132
4 15.25 17.50 19.00
(***) For Decks utilizing prestressed panels.


Image:751.14 section thru haunch showing shear connectors.gif
Image:751.14 clearance at expansion device for shear connectors.gif Image:751.14 clearance at splice plate for shear connectors.gif
Section Thru Haunch Clearance at
Expansion Device
Clearance at
Splice Plate
Image:751.14 circled 6.gif For redecks of existing composite bridges #4 hairpin bars required if depth exceeds 2" for existing 4" shear connectors and 3" for existing 5" shear connectors. For new bridges and redecks of non-composite bridges, studs shall provide a minimum 2” slab embedment avoiding the need of hairpin bars.


Shear Connector Unit


P/C P/S Panel Forms on Steel Structures

Use precast prestressed panels on all tangent steel structures. Evaluate the viability of the use of P/S panels on curved structures on a case by case basis and use or include as an option to a CIP slab where deemed appropriate.

Whenever panels are used, the minimum top flange width shall be 12" for plate girders and 10" for wide flange beams.

Steel girders shall be cambered when using P/S Panels. Minimum joint filler thickness is 1", except over splice plates, in which case use 1/4" minimum. Maximum joint filler thickness is 2", except over splice plates, in which case use 1".

Shear connectors shall have a minimum height equal to the top of panel.

Shear connectors shall be spaced by units and shear connectors in each unit shall be placed along centerline (\, C_{\!\!\!\!L}) of girder. On wide flange widths, two lines of connectors may be used if spacings and clearances allow.

Additional shear connectors, Nac, at point of contraflexure may be placed in units normal to centerline of girder as space allows or in a single row along centerline of girder as shown below:

Image:751.40 Widen and Repair Design Assumptions- PCP on Steel Shear Connector.gif


P/S strands shall extend 3" minimum and 6" maximum past edge of precast prestressed panel and not closer than 1" to the adjacent panels.

Panel end at splices shall be notched to avoid bolt heads as shown below:

Image:751.40 Widen and Repair Design Assumptions- PCP on Steel Shear Connector- B.gif

Image:751.40 circled 1.gif 3/4" min. wide bearing edge for panel at splice, typ.

Image:751.40 circled 2.gif 1-1/4" min. (Typ.)

Image:751.40 circled 3.gif 4 x (Stud diameter) preferred minimum, may be reduced if necessary for a more economical design; 2-1/4" absolute minimum.


* In order to meet Image:751.40 circled 1.gif and Image:751.40 circled 2.gif above, it is necessary to have an edge bolt distance of 2" or greater for splice plate.

Minimum joint filler thickness is 1" except over splice plates in which case use 1/4" minimum. Use 3/4" joint filler width for panels over splice plates. When joint filler is less than 1/2" thick over splice plate, the contractor is required to make the width of joint filler at splice the same width as panel on splice.

Maximum difference in top of flange thickness should be checked so that joint filler thickness does not exceed 2".

751.14.5 Details

751.14.5.1 Bearing Stiffeners

Refer to EPG 751.14.5.10 for weld design and detail guidance.

Bearing Stiffener Connections - No End
Diaphragms or Cross Frames Attached


Bearing Stiffener Connections - End
Diaphragms or Cross Frames Attached
(Preferred Detail. Design required.)


Bearing Stiffener Connections - End
Diaphragms or Cross Frames Attached
(Optional Detail. Design required.)
  • Optional clip angle connection shall include fatigue investigation and diaphragm moment effects due to bridge skew and curvature effects.
  • Bearing stiffener plate size by design (1/2" thick minimum).


Locations Refer to EPG 751.14.5.10 for weld design and detail guidance.

Image:751.14 End Diaphragms – Skews Thru 25°-Cross Frames – Skews Thru 20°.gif
End Diaphragms – Skews Thru 25°
Cross Frames – Skews Thru 20°


Image:751.14 End Diaphragms – Skews Over 25° Thru 45°.gif
End Diaphragms – Skews Over 25° Thru 45°


Image:751.14 End Diaphragms – Skews Over 45°.gif
End Diaphragms – Skews Over 45°


Image:751.14 End Diaphragms – All Skews-Cross Frames – Skews Thru 20°.gif
End Diaphragms – All Skews
Cross Frames – Skews Thru 20°



Welds for Optional Stiffener Locations Refer to EPG 751.14.5.10 for weld design and detail guidance.

Image:751.14 connection a.gif
Connection “A”


Image:751.14 connection b.gif
Connection “B”


Image:751.14 connection c.gif
Connection “C”



Connection Angle Details for Optional Stiffener Connection

Image:751.14 connection angle details-front elevation and section thru angle.gif
Front ElevationSection Thru Angle
 
Image:751.14 connection angle details-plan.gif Image:751.14 connection angle details-section thru angle for birdges on vertical grade.gif
Plan Section Thru Angle
Bridges on
Vertical Grade
(*)Angle legs shall be adjusted to conform to the variable angle between bearing stiffener and top flange created by the girder tilt requirement due to vertical grade.
(**)1/2" for W21 and W24 wide flange beam shapes. 1 1/2" for all other wide flange beams and plate girders.
(***)3” for W21 and W24 wide flange beam shapes. 4” for all other wide flange beams and plate girders.


Bearing Stiffener Connections For Given Skew And Stiffener Size
 Stiffener Thickness (in)
Skew 1/25/83/47/811 1/81 1/41 3/81 1/21 5/81 3/41 7/822 1/82 1/42 3/82 1/22 5/8
0° THRU 5° AAAAAAAAAAAAAABBBB
6° THRU 10° AAAAABBBBBBBBBBBBB
11° THRU 15° AABBBBBBBBBBBBBBBB
16° THRU 20° ABBBBBBBBBBBBBBBBB
21° THRU 25° BBBBBBBBBBBBBBBBBB
26° THRU 30° BBBBBBBBBBBBBBBBBB
31° THRU 35° CCCCCCCCCCCCCCCCCC
36° THRU 40° CCCCCCCCCCCCCCCCCC
41° THRU 45° CCCCCCCCCCCCCCCCCC

751.14.5.2 Int. Diaphragms and Cross Frames

Refer to EPG 751.14.5.10 for weld design and detail guidance.

Note: For intermediate diaphragm connection plate, see EPG 751.14.5.5 Transverse Stiffeners.
 Intermediate Diaphragm Connection Plate
(Preferred Detail. Design required.)
 
Optional clip angle shall include fatigue investigation and diaphragm moment effects due to bridge skew and curvature effects.
 Intermediate Diaphragm Connection Plate
(Optional. Design required.)
Connection Angle Details (See table below for "A" and "B" values.)
Image:751.14 flange connection angles-front elevation and section thru.gif Image:751.14 flange connection angles-plan.gif
Front Elevation
Detail of Flange
Connection Angle
Section thru Flange
Connection Angle
6 x 6 x 3/8
Plan Detail of Flange
Connection Angle


Diaphragm Details

Image:751.14 diaphragm connection details.gif
*When angles are required verify clearance for cross slope.
6 1/4" (Min.) for wide flanges
6 1/2" (Min.) for plate girders
See table below for "D" and "N" values.
Diaphragm Connection at Stiffener Detail
Note:The above details are assumed adequate for straight girders. Horizontally curved girders require design for torsional effects (see Analysis of Horizontally Curved Girders)


Fill Plate Detail - PreferredOptional Fill Plate Detail for Contractor
Note:The Top and bottom tension or compression flanges should be shown on the “Elevation of Girder” detail on plans.

Refer to EPG 751.14.5.10 for weld design and detail guidance.

Intermediate Diaphragm and Cross Frame Details **
Shape"D" (in)"N"Channel, Angle
or Bent Plate
"A" (in)"B" (in)
W21X48 THRU W21X93124C12 x 20.731/2
W24X68 THRU W24X103124C12 x 20.731/2
W27X84 THRU W27X1291545/16 x 2341 1/2
W30X90 THRU W30X1481855/16 x 2641 1/2
W33X118 THRU W33X2212155/16 x 2941 1/2
W36X135 THRU W36X1942155/16 x 2941 1/2
W40X149 THRU W40X2152155/16 x 2941 1/2
36" thru 40" Plate Girders2155/16 x 2941 1/2
42" Plate Girders2755/16 x 3541 1/2
> 42" Plate GirdersDiagonal MemberL3x3x5/1641 1/2
Horizontal
Member
*** S < 10'-2"L3.5x3.5x5/16
otherL4x4x5/16
**Table is applicable for diaphragms and cross frames used as bracing members. For criterion used in determining members sizes see the footnotes for the “Bottom Horizontal Members for Web Depths” and “ Diagonal Members for Web Depths > 48” tables for End Diaphragms.
***S = girder spacing along diaphragm skew
Diaphragms and cross frames used as primary members must be checked for torsion effects. (See Analysis of Horizontally Curved Girders)
ATTENTION DETAILER:
Intermediate diaphragm connection plates shall be detailed for Connection “A” for skews thru 20˚.
Details of Connection “A” are shown in [[#751.14.5.1 Bearing Stiffeners|EPG 751.14.5.1 Bearing Stiffeners].

751.14.5.3 End Diaphragms for Wide Flange Beams

W21 thru W30Stringer Spacing, ft.
Skew, deg.77.588.599.51010.5
0C15x33.9C15x33.9C15x40C15x50C15x50W16x36W16x40W16x40
10C15x33.9C15x40C15x40C15x50C15x50W16x36W16x40W16x40
20C15x33.9C15x40C15x50C15x50W16x36W16x40W16x40W16x45
30C15x40C15x50C15x50W16x36W16x40W16x40W16x45W16x45
40C15x50W16x36W16x40W16x45W16x45W16x50W16x50W16x57
50W16x40W16x45W16x50W16x50W16x57W16x57W16x67W16x67
60W16x57W16x67W16x67W16x67W16x67W16x77W16x77W16x89


W33Stringer Spacing, ft.
Skew, deg.77.588.599.51010.5
0W16x31W16x31W16x31W16x36W16x36W16x36W16x40W16x40
10W16x31W16x31W16x31W16x36W16x36W16x36W16x40W16x40
20W16x31W16x31W16x36W16x36W16x36W16x40W16x40W16x45
30W16x31W16x36W16x36W16x36W16x40W16x40W16x45W16x45
40W16x36W16x36W16x40W16x45W16x45W16x50W16x50W16x57
50W16x40W16x45W16x50W16x50W16x57W16x57W16x67W16x67
60W16x57W16x67W16x67W16x67W16x67W16x77W16x77W16x89


W36Stringer Spacing, ft.
Skew, deg.77.588.599.51010.5
0W18x35W18x35W18x35W18x35W18x35W18x35W18x40W18x40
10W18x35W18x35W18x35W18x35W18x35W18x35W18x40W18x40
20W18x35W18x35W18x35W18x35W18x35W18x40W18x40W18x40
30W18x35W18x35W18x35W18x35W18x40W18x40W18x46W18x46
40W18x35W18x35W18x40W18x40W18x46W18x46W18x50W18x50
50W18x40W18x46W18x46W18x50W18x50W18x55W18x55W18x60
60W18x50W18x55W18x60W18x65W18x65W18x71W18x76W18x76


W40 thru W44Stringer Spacing, ft.
Skew, deg.77.588.599.51010.5
0W21x44W21x44W21x44W21x44W21x44W21x44W21x44W21x44
10W21x44W21x44W21x44W21x44W21x44W21x44W21x44W21x44
20W21x44W21x44W21x44W21x44W21x44W21x44W21x44W21x44
30W21x44W21x44W21x44W21x44W21x44W21x44W21x44W21x44
40W21x44W21x44W21x44W21x44W21x44W21x44W21x44W21x48
50W21x44W21x44W21x44W21x44W21x48W21x48W21x55W21x55
60W21x48W21x50W21x55W21x55W21x62W21x62W21x68W21x73
Note:The values in the table above may be used for both straight and horizontally curved beams.


Image:751.14 End Diaphragm Connections for W21 thru W24 Beams.gif
End Diaphragm Connections for W21 thru W24 Beams


End Diaphragm Connections for W27 thru W40 Beams

Refer to EPG 751.14.5.10 for weld design and detail guidance.


(*)Slope diaphragms when structure is superelevated or when 4” maximum depth is exceeded. See EPG 751.13 Expansion Devices for the details of end diaphragms on a structure.
(**)Modify if necessary to clear the anchor bolts of the flat plate bearing or connection bolts of the expansion device.


All Sizes

Image:751.14 plan of end diaphragm connection for steel structures.gif


ATTENTION DETAILER:
End diaphragms shall be detailed horizontally, stepped, or sloped as required.

751.14.5.4 End Diaphragms for Plate Girders

Top Horizontal Members for Given Web Depths
Webs Thru 40"Girder Spacing, ft.
Skew, deg.77.588.599.51010.5
0W21x44W21x44W21x44W21x44W21x44W21x44W21x44W21x44
10W21x44W21x44W21x44W21x44W21x44W21x44W21x44W21x44
20W21x44W21x44W21x44W21x44W21x44W21x44W21x44W21x44
30W21x44W21x44W21x44W21x44W21x44W21x44W21x44W21x44
40W21x44W21x44W21x44W21x44W21x44W21x44W21x44W21x48
50W21x44W21x44W21x44W21x44W21x48W21x48W21x55W21x55
60W21x48W21x50W21x55W21x55W21x62W21x62W21x68W21x73


Webs >= 42"Girder Spacing, ft.
Skew, deg.77.588.599.51010.5
0C15x33.9C15x33.9C15x40C15x50C15x50W16x36W16x40W16x40
10C15x33.9C15x40C15x40C15x50C15x50W16x36W16x40W16x40
20C15x33.9C15x40C15x50C15x50W16x36W16x40W16x40W16x45
30C15x40C15x50C15x50W16x36W16x40W16x40W16x45W16x45
40C15x50W16x36W16x40W16x45W16x45W16x50W16x50W16x57
50W16x40W16x45W16x50W16x50W16x57W16x57W16x67W16x67
60W16x57W16x67W16x67W16x67W16x67W16x77W16x77W16x89


Bottom Horizontal Members for Web Depths ≥ 42”
Webs >= 42"Girder Spacing, ft.
Skew, deg.77.588.599.51010.5
0 thru 10L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L4x4x5/16L4x4x5/16L4x4x5/16L4x4x5/16
20L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L4x4x5/16L4x4x5/16L4x4x5/16L4x4x5/16
30L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L4x4x5/16L4x4x5/16L4x4x5/16L4x4x5/16L4x4x5/16L5x5x5/16
40L3 1/2x3 1/2x5/16L4x4x5/16L4x4x5/16L4x4x5/16L5x5x5/16L5x5x5/16L5x5x5/16L5x5x5/16
50L4x4x5/16L4x4x5/16L5x5x5/16L5x5x5/16L5x5x5/16L5x5x5/16L6x6x3/8L6x6x3/8
60L5x5x5/16L5x5x5/16L6x6x3/8L6x6x3/8L6x6x3/8L6x6x3/8WT6x17.5WT6x17.5


Diagonal Members for Web Depths > 48”
Webs <= 60"Girder Spacing, ft.
Skew, deg.77.588.599.51010.5
0 thru 50L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16
60L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16


Webs < 112"Girder Spacing, ft.
Skew, deg.77.588.599.51010.5
40L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16L3x3x5/16
60L3x3x5/16L3x3x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16L3 1/2x3 1/2x5/16


For girder spacing or skews not listed in table, use nearest tabulated angle size.

Enter the tables with the skew of the diaphragm, not the bridge skew.

The members in Tables 2 and 3 were selected to meet only the slenderness requirement \, \frac {K l}{r_z} \le 140. For diagonal bracing members the following \, K values were used for equal leg single angle members:

L3x3x5/16\, K= 0.85
L3 1/2x3 1/2x5/16 and longer leg lengths\, K= 0.75


For horizontal bracing members the following K values were used for equal leg single angle members:

L3x3x5/16\, K= 1.1
L3 1/2x3 1/2x5/16\, K= 0.95
L4x4x5/16\, K= 0.85
L5x5x5/16\, K= 0.80
L6x6x3/8\, K= 0.75


The above \, K values were determined using the following reference article: “Critical Slenderness of Compression Members with Effective Lengths about Nonprincipal Axes”, L. A. Lutz (1992)

For WT shapes: \, K = 0.75 (in-plane), 1.0 (out-of-plane)

Member lengths, l, were measured from the center of bolted connection. The center of bolted connection is assumed to be located 3.5” perpendicular to CL web. Vertically, diagonal members are assumed to extend to 2 3/8” from outer gusset plate edge. In-plane bending was assumed to be fixed-fixed while out-of-plane bending is assumed to be pinned at the bolted connection and fixed at the diagonal member crossing. Diagonal members are assumed to be braced in the middle.

For diaphragms and cross-frames designed as primary members in horizontally curved girders:

\, \frac{Kl}{r} \le 120

Primary members shall also be designed for torsional effects. (See Analysis of Horizontally Curved Girders)


End Diaphragms

Image:751.14 end diaphragm - 36in thru 40in webs.gif
End Diaphragm - 36" Thru 40" Webs
 
Image:751.14 end diaphragm - 42in thru 48in webs.gif
End Diaphragm - 42" Thru 48" Webs
 
Detail "D"Detail "E"
Haunch slab to bear on channel or wide flange.
(*)Slope diaphragms when a structure is superelevated or when the 4" maximum depth is exceeded.

Refer to EPG 751.14.5.10 for weld design and detail guidance.

Image:751.14 end diaphragm - webs over 48in.gif
End Diaphragm - Webs Over 48"
 
Detail "C"Detail "A"
Haunch slab to bear on channel or wide flange.
(*)Slope diaphragms when a structure is superelevated or when the 4" maximum depth is exceeded.

Refer to EPG 751.14.5.10 for weld design and detail guidance.

Image:751.14 end diaphragm - webs over 48in structure with finger plate expansion device.gif
End Diaphragm - Webs Over 48"
Structure with Finger Plate Expansion Device
 
Detail "D"Detail "A"

Refer to EPG 751.14.5.10 for weld design and detail guidance.

751.14.5.5 Transverse Stiffeners

Int. web Stiffener (One Side Only)
Variable Flange Width
 
Refer to EPG 751.14.5.10 for weld design and detail guidance.
Image:751.14 details thru bevel plate for int web stiffener-brg stiffener-and int diaphragm connection plates.gif
Details Thru Bevel Plate for Int. Web Stiffener, Bearing
Stiffener and Intermediate Diaphragm Connection Plates
(1)Check LRFD 6.10.11.1.1 for clip limits
(*)When dimension exceeds 1/2", bevel stiffener plate.
(**)Attach to flange for girders designed as horizontally curved (see Analysis of Horizontally Curved Girders)
Note: For intermediate web stiffener and intermediate diaphragm connection plate, use 1/2" minimum thickness.
  Use 5 1/2" minimum width stiffener.
  Width of plate shall be increased as required by 1/2" increments. Thickness of plate shall be increased as required by 1/8" increments when required thickness exceeds 1/2".
  Transverse stiffeners shall be used on inside face of exterior girders and in successive alignment along either side of interior girders.
  Top and bottom tension or compression flanges should be shown on the "Elevation of Girder" detail on plans.

751.14.5.6 Longitudinal Stiffeners

When longitudinal stiffeners are required they shall be used on the outside of exterior girders and in successive alignment along either side of interior girders.
The placement of longitudinal stiffeners may interfere with bolting the diaphragm or cross frame in place. Should this occur, it will be necessary to clip the longitudinal stiffeners as shown below.
Also, when lateral bracing is required, place the longitudinal stiffener on the opposite side of girder.
The appropriate details shown below shall be modified as needed and placed on the design plans.
(*) Location shall satisfy requirements of LRFD 6.10.8.3.
  Longitudinal Web Stiffener
(One Side Only)
Refer to EPG 751.14.5.10 for weld design and detail guidance.


Image:751.14 section showing longitudinal stiffeners at vertical stiffeners and connection plates.gif
Interior Girders
Square or Skewed
Exterior Girders
at Intermediate
Bearing Stiffeners
 
Image:751.14 section showing longitudinal stiffeners at bolted field splice.gif
Typical Section at Bolted Field Splice

751.14.5.7 Lateral Bracing

Lateral bracing shall be omitted on all spans \, < 140 ft. Lateral bracing may be omitted on spans \, \ge 140 ft provided the girder meets all applicable Strength limit states.

Lateral bracing shall be placed in outer bays.

Members selected shall meet requirements of bracing members with \, KL/r \le 140.

Under no circumstance shall lateral bracing be detailed to go through diaphragms. In order to facilitate erection, structural tees for lateral bracing may be inverted to connect to the top gusset plates.

Whenever practicable, diaphragms and lateral bracing shall connect to bearing stiffeners in bridges having large skews, diaphragms and lateral bracing need not connect to end bearing stiffeners for such structures but should connect to a girder midway between the bearing stiffener and the first transverse web stiffener.


Image:751.14 part lateral bracing framing plan1.gif
Part Lateral Bracing Framing Plan
See below for Details "B" & "C"


Image:751.14 lateral bracing detail b.gif
Image:751.14 circled 1.gif Spaced at 2" (Min.), 3" (Max.)
Detail "B"
 
Image:751.14 lateral bracing detail c.gif
Detail "C"Detail "A"
Note:Lateral Bracing T-Gusset shall be cut to required depth from W27 x 94, or T-Gusset can be built from plates in shop.
Refer to EPG 751.14.5.10 for weld design and detail guidance.


Image:751.14 lateral bracing-constant depth girders.gif
(*)Locate T-Gusset as shown above, dimension at all connections should be constant from top of bottom flange.
Place following not on plans:Note: T-Gusset shall be placed (*) inches above top of bottom flange.
Constant Depth Girders
 
Image:751.14 lateral bracing-constant-variable depth girders.gif
(**)Locate T-Gusset as shown above, dimension at all connections should be constant from top of bottom flange in constant web depth portions.
Constant - Variable Depth Girders
 
Image:751.14 lateral bracing-tapered-variable depth girders.gif
(***)Locate T-Gusset as shown above, dimension at all connections thru tapered section should be constant from top of bottom flange (Slope T-Gusset same as bottom flange). Continue same slope through variable depth section of girders.
Tapered - Variable Depth Girders

751.14.5.8 Protective Coating Requirements

Coating requirements for new steel girder bridge shall be in accordance with Sec 1080 and Sec 1081.

System G (three-coat system) is typically used for non-weathering steel (Sec 1081).

System H (three-cost system) is typically used for weathering steel (Sec 1080 and Sec 1081) or where coating operations will take place near an existing vinyl coating system (System C).

System I (two-coat system) shall be used for non-weathering steel only and should be based on the following guidance:

(a) System I should be considered in areas where the aesthetics of a coating system over the long term is unusually more critical than System G. While System G and I provide long term protection, System I has excellent gloss retention and UV resistance. System I is a context sensitive design (CSD) solution. CSD follows from project scoping and is subject to the project core team protocols.
(1) Consider for locations where the structure is more visible or the public has leisurely time for more than just a casual glance, for example structures near a ballpark or a pedestrian bridge. Using same rationale, bridges that are tall or have wide girder spacing or a low number of girders where more of the superstructure is visible could also be candidates.
(2) Consider the image consciousness of the surroundings in conjunction with rather than solely the protection of the structure which is equally provided by both systems. Maintenance of either System G or I should be considered the same.
(b) System I is a polysiloxane finish coat that is normally applied directly over an inorganic zinc primer with no intermediate coating. Since the system is a two-coat system, it may be applied in less time which can influence critical path scheduling and impacts to the driving public. For example, it may be possible for a contractor to get in and out quicker than if they were to use a three-coat system. MoDOT coating policy as described in Standard Specification Section 1081 requires different field coating requirements based on the type of bridge crossing. For roadway grade separations, it is required that interior girders have only a single field coat in order to satisfy that all girders on a roadway grade separation bridge have at least two coatings for protection. In the case of System I, the Standard Specifications require that a System G epoxy intermediate field coat be applied to all interior girders and the interior of fascia girders and that the System I polysiloxane finish coating be applied to the exterior of the facia girders only. This is based on a system I polysiloxane coating cost being greater than a system G epoxy coating on a per-gallon cost basis. It also requires that the contractor be given the option to substitute the System I finish coat in place of a System G intermediate coat. If CSD determines that the polysiloxane should to be applied to all girders, then the general notes for coatings and the quantities on the contract plans will need to reflect the revised coating requirements.
(c) System I is approved for use on state highway projects beginning February 2011. Alternate bidding is encouraged if guideline (a) is not required to be met and with approval of the Structural Project Manager or Structural Liaison Engineer and the project core team.

See EPG 751.50 A4. Protective Coatings for standard detailing notes and guidance on how they are used.

751.14.5.9 Weathering Steel

Use of weathering steel may require special detailing as specified in the referenced documents in EPG 751.1.2.7.

751.14.5.9.1 Drip Bar Guidance

General

The purpose of a drip bar placed on the bottom flange is to intercept and deflect water and debris. Drip bars should be installed on new, or retrofitting existing weathering steel where a need is discovered.

Drip bars should be utilized for three reasons:

1. To protect girders and beams from sustained and accumulated (heavy) water flow along the web-flange crease that can promote deterioration by wearing action (due to particulate matter and debris) and long term moisture retention along the crease and along the lower web whereby water is drawn up the sides of the lower web by capillary action which is observable in the field as constantly "wetted" sides or permanent discoloration. For a new girder or beam, this can retard the development of or reduce the efficacy of the protective oxide coating.

2. To protect bearing devices from sustained moisture due to accumulating water and debris.

3. To protect substructure from long term staining. (For the short term, temporary protective coating is utilized during weathering steel construction; see EPG 711 Protective Coatings for Exposed Concrete Surfaces.)

Guidance

Drip bars shall not be provided on flat structures (0.0 % grade) unless in the case of long spans where permanently cambered girders or beams can produce a water flow.

Drip bars shall be placed skewed on top of bottom flange and preferably placed squared on bottom of bottom flange.

Drip bars shall not be provided directly over railroads, roadways and walkways.

(Case 1) To protect girders and beams: Drip bars should be located at the downgrade side of open or closed expansion devices between 5 ft. from the center of the expansion device and to within 1 ft. from the end of the partial coating limit (to ensure the drip bars are coated) for all girders or beams within a span.

(Case 2) To protect girder and beam ends, bearings and bearing stiffeners: Drip bars should be located at the upgrade side of bearings at the exterior faces of exterior girders or beams at about 4 ft. away from the face of the bent for downhill runs of 100 ft. or longer span girders or beams.

(Case 3) To protect substructure: Drip bars should be located adjacent to the upgrade side of the bent at the exterior faces of exterior girders or beams at about 4 ft. away from the face of the bent for downhill runs of 100 ft. or longer span girders or beams to prevent stain marks on the substructure in either urban or context sensitive designs, for example where the aesthetics of the structure is considered important. For aesthetics reasons drip bars adjacent to substructure may be provided where the structure is over railroad, water or near integral abutments.

Fatigue analysis of girder or beam for welded connection of drip bars shall be required in the event that there will be effective stress cycles in tension and/or stress reversal on the welds. Bolted drip angle details may be considered instead of welded drip bars details as an alternative.

Notes:
Identify direction of grade on plans and orient drip bar accordingly to deflect water and debris.
Case 1 - Provide drip bar detail at all girders to block water from expansion device to protect the girders.
Case 2 or 3 - Provide drip bar detail at exterior face of exterior girders to deflect water and debris from 100 ft. or longer span draining to a bent.

751.14.5.9.2 Drip Bar Details

Bridge Standard Drawings – Drip Bar
Welded Drip_Bar Details (Preferred)
Bolted_Drip_Angles Details (Optional)

Welded drip bar details are preferred because they are simpler, require less work and produce less damage to new or existing weathering steel flanges. Bolted drip angles are optional and should only be used when welded drip bars cannot be used. Both sets of details are not intended to be used as alternates on a single job.

751.14.5.10 Weld Design and Detail Guidance

General

Fillet Welds

Weld design and detail guidance is provided to ensure that the correct fillet weld size is used for fabrication and to reduce incidences of inconsistent and/or incorrect fillet weld sizes shown on the plans which can cause problems for both designer and fabricator.

Preferred MoDOT standard practice is to exclude (leave blank) fillet weld sizes from the bridge plans which is to mean that the fillet weld size shall be determined by the fabricator and that they are contractually obligated to use the minimum fillet weld sizes given in Sec 1080 (shown as the minimum size of fillet weld) of the Standard Specifications.

Excluding fillet weld sizes from the bridge plans is correct in most situations, for example routine welded connections. This accepted and preferred practice prevents the designer from performing unnecessary and complicated load estimates and weld strength computations for mundane welded connections while ensuring consistent plan details for ease of fabrication. Standard Drawings and the details shown in EPG 751.14.5 Details show fillet weld symbols without the fillet weld size and should be assumed adequate for typical applications. Minimum fillet weld sizes are based only on material thickness of parts to be adjoined and are not specific to loading condition or magnitude of load, and are proven empirically to work in practice for typical applications. For more information, see itemized guidance following.

However, excluding fillet weld sizes shall not preclude sound engineering practice of ensuring that a minimum fillet weld size given in accordance with Sec 1080 is acceptable to resist maximum factored loads. This is for typical applications only – ALWAYS CHECK to be sure.

Specialty Welds

For purposes of this section only, any weld not a fillet weld is considered a specialty weld and weld symbol should include all pertinent design information and instruction for fabricating weld, i.e. type, size and instructions.

Itemized Guidance

Itemized guidance is provided to be used for all types of welds.

No. 1 Weld design shall be in accordance with AISC Steel Construction Manual, 13th Ed., Part 8; AASHTO LRFD Bridge Design Specifications, Bridge Welding Code AASHTO/AWS D1.5M/D1.5 Bridge Welding Code, Missouri Standard Specifications Sec 1080 and EPG 751.5.9 Welding Details.
No. 2The minimum fillet weld size for welding connections shall not be less than the size required by design to resist the maximum factored loads in accordance with LRFD 6.13.3 nor the minimum fillet weld size shown in Sec 1080.
No. 3 Design of welds shall include fatigue investigation and diaphragm moment effects due to bridge skew and curvature effects if applicable. For routine* plate girders and wide flange beams, leave the weld size blank for the stiffener to web weld and use the requirements in the Standard Specifications. For curved plate girders, skews greater than 50° and spans longer than 200 ft., the stiffener to web fillet weld size should be investigated.
* Judgment and experience are required to determine this; guidance is provided and may not be strict enough in characterizing nonroutine (or nontypical) bridges.
No. 4Fillet weld size for weld connections shall not be shown on the plans if minimum required fillet weld size by design is less than or equal to fillet weld size shown in Sec 1080. (Fabricators and inspectors will use the minimum fillet weld size given in Sec 1080 unless larger fillet weld size is shown on the bridge plans.)
No. 5Seismic design effects shall also be considered for design of welds when required.
No. 6Fillet weld size shall be shown on the bridge plans for specialty weld connections, for example, as shown in EPG 751.14.5.3 End Diaphragm Connection for W27 thru W40 beams and EPG 751.14.5.4 End Diaphragm for Plate Girders, Detail “D”. Specialty welds as shown shall be checked for conditions given in No. 4.
No. 7Working clearance requirements to allow adequate room for welder to make proper welds shall be checked in accordance with AISC Steel Construction Manual, 13th Ed., Part 8; AASHTO Bridge Design LRFD Specifications and Bridge Welding Code AASHTO/AWS D1.5M/D1.5 Bridge Welding Code.
No. 8 Field weld symbols should be shown with fillet weld size. In general, field welding symbols should be shown complete, i.e. include all pertinent design information and instruction for fabricating weld, i.e. type, size and instructions.
No. 9Angle size for steel diaphragms should be shown without inch (“) marks on the plans.
Examples of Design and Detail of Bearing Stiffener Fillet Welds
Ex. 1 Routine Bridge – Nonseismic
Check No. 3 Routine by criteria (given); no weld size check necessary.
Check No. 4 Leave weld size blank but show weld symbol.
Check No. 7 Check working clearances. Is there adequate clearance to make the weld?
Ex. 2 Nonroutine Bridge – Nonseismic
Check No. 3 Nonroutine by criteria (given); weld size check necessary using No. 1 and No.2; if design fillet weld size <= minimum fillet weld size shown in Sec 1080, do not show fillet weld size (leave blank) on plans, but do show fillet weld symbol.
Check No. 4 Insert design fillet weld size if design fillet weld size > minimum fillet weld size shown in Sec 1080.
Check No. 7 Check working clearances. Is there adequate clearance to make the weld?
Ex. 3 Nonroutine Bridge – Seismic
Check No.4Nonroutine by criteria (given); weld size check necessary using No. 1 and No. 2. Seismic; Consult with Structural Project Manager or Structural Liaison Engineer to consider developing loads and designing fillet weld size; If design fillet weld size < minimum fillet weld size shown in Sec 1080, do not show fillet weld size (leave blank) on plans, but do show fillet weld symbol.
Check No. 5 Insert design fillet weld size if design fillet weld size > minimum fillet weld size shown in Sec 1080.
Check No. 7 Check working clearances. Is there adequate clearance to make the weld?

751.14.6 Miscellaneous Details

751.14.6.1 Girder Haunch

Prestressed Panel Section:
Steel girders shall be cambered when using P/S Panels.
Image:751.14 girder haunch-prestressed panel section.gif
 
Cast-in-Place Section:
Cambering steel girders is preferred over varying the haunch profile. For wide flange beams with nominal depths ≥ 36 in., the cambering method required by the fabricator may not be economical and should be compared to the cost of using variable haunching. When variable haunching is used in lieu of cambering, the maximum haunch limit may be maintained by changing girder slopes at field splices.
Slab Haunch Limits:
Image:751.14 girder haunch-cast-in-place section crowned roadway.gif Image:751.14 girder haunch-cast-in-place section superelevated roadway.gif
Normal Crown
Roadway Slab
Superelevated
Slab
(*)1/2 in. minimum edge clearance except over splice plates use 1/4 in. min.

751.14.6.2 Girder Camber and Dead Load Deflection

Straight Grade (Dead Load Deflection)
Compute Dead load Deflection at 1/4 points for bridges with spans less than 75', at 1/10 points for spans 75' and over.
 Image:751.14 girder camber and dead load deflection-theoretical slab haunch.gif
 Theoretical
Slab Haunch
Theoretical
Slab Haunch
 (P/C P/S Panel Section)(C.I.P. Section)
(*) Dimension (bottom of slab to top of web) may vary if girder camber after erection
differs from plan camber by more than the % of Dead Load Deflection due
to weight of structural steel. No payment will be made for any adjustment in forming
or additional concrete required for variation in haunching.
 
 Image:751.14 girder camber and dead load deflection-plate girder camber diagram.gif
 Plate Girder Camber Diagram
Note:Camber included allowance for _______________. (**)
 ___% of dead load deflection due to weight of structural steel.
(**)Provide proper notes.



Vertical Curves(Dead Load Deflection)
 Image:751.14 vertical curves (dead load deflection)-theoretical slab haunch.gif
 Theoretical
Slab Haunch
Theoretical
Slab Haunch
 (P/C P/S Panel Section)(C.I.P. Section)
(*) Dimension (bottom of slab to top of web) may vary if girder camber after erection
differs from plan camber by more than the % of Dead Load Deflection due to
weight of structural steel. No payment will be made for any adjustment in forming
or additional concrete required for variation in haunching.
 
 Image:751.14 vertical curves (dead load deflection)-plate girder camber diagram.gif
 Plate Girder Camber Diagram  
 Image:751.14 vertical curves (dead load deflection)-plate girder deflection diagram.gif
 Plate Girder Deflection Diagram
Note:Camber included allowance for _______________. (**)
 ___% of dead load deflection due to weight of structural steel.
(**)Provide proper notes.

751.14.6.3 Girder Elevation Variation Sketch

Image:751.14 girder elevation variation sketch-section thru girders normal to cl roadway.gif
Section Thru Girders Normal To Centerline Roadway
Image:751.14 girder elevation variation sketch-table.gif


Dimensions showing girder variations shall be placed on the cross section thru slab or, if necessary because of the number and type of variations, the above type of detail and table shall be placed near the structural steel layout.

751.14.6.4 Spacing of Intermediate Diaphragm from Splice

Image:751.14 spacing of intermediate diaphragms from splice.gif


751.14.6.5 Offsets for Curved Plate Girders

Plans for structures having horizontally curved plate girders shall have the detail shown below placed near the plan of structural steel.


Image:751.14 part plan of structural steel showing cl girder curve offsets.gif
Part Plan of Structural Steel Showing
Centerline Girder Curve Offsets


Note:Typical example for 3 span structure shown.
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