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COMMONWEALTH OF PENNSYLVANIADEPARTMENT OF TRANSPORTATION

STANDARD

WITH REFINED METHODS OF ANALYSIS

CROSS FRAME AND SOLID PLATE

DIAPHRAGMS FOR STEEL BEAM/GIRDER

BRIDGES DESIGNED

BD-619M

SHEET 1 OF 5

CHIEF BRIDGE ENGINEER

RECOMMENDEDRECOMMENDED

BUREAU OF PROJECT DELIVERY

S

ANY SPAN LENGTH

RECOMMENDED ACCEPTABLE AVOID

ANY NONE

ANY SPAN LENGTH

RECOMMENDED ACCEPTABLE AVOID

NLF

S

TDLF OR SDLF

RECOMMENDED ACCEPTABLE AVOID

NLF

S

SPAN LENGTHS 200 FEET

SPAN LENGTHS 200 FEET

TDLFSDLF

SDLF TDLF & NLF

MAX

RECOMMENDED ACCEPTABLE AVOID

SDLF

BRIDGES WITH RADIAL OR SKEWED SUPPORTS

MAX

ALL OTHER CASES NLF TDLF

(INCLUDING BRIDGES WITH L/R IN ALL SPANS LESS THAN 0.03 +/-)

RECOMMENDED FIT CONDITIONS FOR STRAIGHT I-GIRDER BRIDGES1

TDLFSDLFNLF

SKEWED BRIDGES WITH SKEW 70 DEGREES +/- AND I 0.30 +/-

SKEWED BRIDGES WITH SKEW 70 DEGREES +/- AND I 0.30 +/-

NON-SKEWED BRIDGES AND SKEWED BRIDGES WITH SKEW 70 DEGREES +/-

1

2

[(L/R) 0.03 +/-]

RECOMMENDED FIT CONDITIONS FOR HORIZONTALLY CURVED I-GIRDER BRIDGES

AND (L/R) 0.1 +/-

LARGE SPAN LENGTHS 250 FEET +/-

NOTES FOR DESIGNING AND DETAILING DIAPHRAGMS

S

NOTES FOR DESIGNING AND DETAILING DIAPHRAGMS, CONTINUED ON SHEET 2* *

REFERENCE DRAWINGS

BC-753M STEEL GIRDER DETAILS

STRUCTURES (STRAIGHT GIRDERS ONLY )

BC-754M STEEL DIAPHRAGMS FOR STEEL BEAM/GIRDER

CONNECTION LOCATION. PROVIDE ROTATION VALUES FOR EACH GIRDER.

DEAD LOAD OUT-OF-PLANE GIRDER ROTATIONS AT THE GIRDER TENTH POINTS AND AT EACH DIAPHRAGM

SURFACE EXCEEDS 0.005 RADIANS, PROVIDE A TABLE IN THE CONSTRUCTION DRAWINGS SHOWING THE TOTAL

b) WHERE THE MAXIMUM OUT-OF-PLANE GIRDER ROTATIONS DUE TO ALL DEAD LOADS, EXCLUDING FUTURE WEARING

SUCCESSFULLY ERECTED IF THE FIT-UP FORCES ARE MANAGEABLE.

ERECTED USING SOME FORM OF TEMPORARY SHORING CAN BE DETAILED FOR SDLF OR TDLF AND

ERECTED IF THE FIT-UP FORCES ARE MANAGEABLE. LIKEWISE, BRIDGES WHICH ARE TO BE

BRIDGES ERECTED WITHOUT TEMPORARY SHORING CAN BE DETAILED FOR NLF AND SUCCESSFULLY

AND MAGNITUDE OF THESE FORCES ARE ALSO INFLUENCED BY THE USE OF TEMPORARY SHORING.

WHICH THE ERECTOR MAY NEED TO APPLY TO ASSEMBLE THE STRUCTURAL STEEL. THE NATURE

MAGNITUDE OF THE BRIDGE'S INTERNAL DEAD LOAD FORCES AND OF THE "FIT-UP" FORCES

SECTION 6, APPENDIX E6, THE CHOICE OF DETAILING METHOD AFFECTS THE NATURE AND

SHORING CANNOT BE USED. AS DISCUSSED IN THE DESIGN AND ANALYSIS SECTION OF DM-4

TEMPORARY SHORING, NOR DOES THE USE OF SDLF OR TDLF DETAILING IMPLY THAT TEMPORARY

2 THE RECOMMENDATION TO USE NLF DETAILING DOES NOT NECESSARILY IMPLY THE NEED TO USE

DISPLACEMENTS BECOME LARGE.

BETWEEN PREDICTED FORCES AND DISPLACEMENTS THAN SDLF WHEN THE STEEL DEAD LOAD

THE NORMAL ANALYSIS METHODS USED IN THE DESIGN AND WILL PROVIDE A BETTER MATCH

FORCES CAN BECOME SIGNIFICANT AS SPANS GET LONGER AND RADII GET SMALLER. NLF MATCHES

NLF ABOVE THIS LENGTH BECAUSE A LIMITED STUDY OF THESE BRIDGES SHOWS CROSS FRAME

UNIVERSAL FOR LONG SPAN CURVED I-GIRDER BRIDGES. THE RECOMMENDATION TRANSITIONS TO

CURVED BRIDGES IS BASED ON MANY YEARS OF PRACTICE: USE OF SDLF HAS BEEN ALMOST

OF THE GIVEN BRIDGE. THE RECOMMENDATION OF SDLF UP TO ABOUT 250' FOR HORIZONTALLY

SHOULD BE EVALUATED IN THE FULL CONTEXT OF THE GEOMETRIC AND STRUCTURAL COMPLEXITY

LENGTH, SKEW, AND CURVATURE LIMITS SHOULD BE CONSIDERED APPROXIMATE GUIDELINES AND

1 FOR THE VARIOUS RECOMMENDED FIT CONDITIONS PRESENTED IN THE TABLES ABOVE, THE SPAN

I = SKEW INDEX, SEE NOTE 7 OF THIS STANDARD FOR DEFINITION.

R = RADIUS OF CURVATURE AT BRIDGE CENTERLINE.

L = ACTUAL SPAN LENGTH, BEARING TO BEARING ALONG THE CENTERLINE OF THE GIRDER.

FUTURE WEARING SURFACE ).

WEIGHT OF STEEL, WEIGHT OF DECK SLAB AND WEIGHT OF SUPERIMPOSED DEAD LOADS, BUT NOT INCLUDING

TDLF = TOTAL DEAD LOAD FIT. GIRDER WEBS VERTICAL (PLUMB ) AFTER ALL DEAD LOADS ARE APPLIED (INCLUDING

GIRDER WEBS VERTICAL (PLUMB ) WITH ALL TEMPORARY SHORING REMOVED.

OF STRUCTURAL STEEL ) BUT PRIOR TO DECK PLACEMENT. IF TEMPORARY SHORING WAS USED, SDLF IMPLIES

SDLF = STEEL DEAD LOAD FIT. GIRDER WEBS VERTICAL (PLUMB ) WHEN STEEL DEAD LOADS ARE APPLIED (WEIGHT

SHORING IS PROVIDED TO ACHIEVE OR APPROXIMATE ZERO VERTICAL DEFLECTIONS )

NLF = NO LOAD FIT. GIRDER WEBS VERTICAL (PLUMB ) UNDER NO LOAD CONDITIONS (I.E., WHEN TEMPORARY

DEFINITIONS:

IN THE TABLES BELOW.

a) GIRDERS SHALL BE DESIGNED AND DETAILED SUCH THAT THE GIRDER WEBS ARE VERTICAL (PLUMB ) AS SPECIFIED

3. DETAILING REQUIREMENTS

PUBLICATION NO. FHWA-IF-12-052-VOL 13, NOVEMBER 2012 (FHWA SBDH).

b) FEDERAL HIGHWAY ADMINISTRATION, STEEL BRIDGE DESIGN HANDBOOK, VOLUME 13, BRACING DESIGN,

a) AISC SPECIFICATION FOR STRUCTURAL STEEL BUILDINGS, ANSI/AISC 360-10, JUNE 22, 2010 (AISC SPEC ).

2. REFERENCES

c) PENNDOT SPECIFICATIONS, PUBLICATION 408 (PUB 408 ).

b) PENNDOT DESIGN MANUAL, PART 4 (PENNDOT DM4 ).

a) AASHTO LRFD BRIDGE DESIGN SPECIFICATIONS (AASHTO LRFD ).

1. DESIGN SPECIFICATIONS

HORIZONTAL (CHORD ) MEMBERS WOULD OTHERWISE BE REQUIRED FOR A TYPE X DIAPHRAGM.

FORCE EFFECTS AND/OR IN CASES WHERE GIRDERS ARE TIGHTLY SPACED AND LARGE DIAGONAL AND

SOLID PLATE: SOLID PLATE DIAPHRAGMS SHOULD BE USED WHEN REQUIRED TO ADDRESS HIGH DIAPHRAGM

REMOVED FROM THEIR FABRICATION JIG AND INVERTED TO WELD THE SECOND DIAGONAL.

ii. MINIMIZING SHOP HANDLING OF DIAPHRAGMS BY USING TYPE K DIAPHRAGMS WHICH DO NOT NEED TO BE

MEMBERS AS CLOSE TO 45 AS POSSIBLE.

i. ACHIEVING A GENERAL EFFICIENT ANGLE BETWEEN DIAPHRAGM DIAGONAL AND HORIZONTAL (CHORD )

TYPE X OR TYPE K DIAPHRAGMS MAY BE USED. SECONDARY CONSIDERATIONS INCLUDE:

IN CASES WHERE THE RATIO OF GIRDER SPACING "S" TO GIRDER DEPTH "D" IS BETWEEN 1.0 AND 1.5, EITHER

DEPTH "D" IS 1.5 OR GREATER (S/D 1.5 ).

TYPE K: TYPE K DIAPHRAGMS SHOULD BE USED IN CASES WHERE THE RATIO OF GIRDER SPACING "S" TO GIRDER

DEPTH "D" IS 1.0 OR LESS (S/D 1.0 ).

TYPE X: TYPE X DIAPHRAGMS SHOULD BE USED IN CASES WHERE THE RATIO OF GIRDER SPACING (S) TO GIRDER

INTERMEDIATE DIAPHRAGMS

SKEW, VARIABLE GIRDER SPACING, ETC.) MAY WARRANT A DEPARTURE FROM THESE GUIDELINES.

DIAPHRAGM TYPES SHOULD BE SELECTED BASED ON THE FOLLOWING GUIDELINES. SPECIAL CONDITIONS (VARIABLE

5. SELECTION OF DIAPHRAGM TYPE

LOCATIONS FOR TWO AND THREE GIRDER SYSTEMS.

m) PROVIDE CONNECTION PLATES ON THE OUTSIDE FACE OF FASCIA GIRDERS AT INTERMEDIATE DIAPHRAGM

SPECIAL DETAILS FOR SKEW ANGLES LESS THAN 25.

l) THE DIAPHRAGM CONNECTION PLATE DETAILS SHOWN ARE VALID FOR SKEW ANGLES 25 TO 90. PROVIDE

GEOMETRY. REFER TO SECTION 1105.03(t) OF PENNDOT PUB 408 FOR MINIMUM BENT RADII.

k) FOR SKEWED CONNECTIONS, THE DESIGNER SHOULD VERIFY THE PRACTICALITY OF BENT CONNECTION PLATE

j) COORDINATE BEARING STIFFENER AND CONNECTION PLATE LOCATIONS WITH DETAILS OF BEARING TO GIRDER CONNECTIONS.

CONNECTION PLATE MAY BE PLACED BEHIND THE BEARING STIFFENER TO MINIMIZE THE OFFSET.

CONNECTION COMPONENTS SO AS TO CREATE MINIMUM OFFSET FROM THE CENTERLINE OF BEARINGS. DIAPHRAGM

i) PLACE END DIAPHRAGMS APPROXIMATELY PARALLEL TO THE CENTERLINE OF BEARINGS. POSITION END DIAPHRAGM

OTHER ACCEPTABLE PROVISIONS FOR JACKING ARE INCORPORATED INTO THE DESIGN.

h) END DIAPHRAGMS SHOULD BE DESIGNED TO ACCOMODATE JACKING OF THE GIRDERS FOR BEARING REPLACEMENT UNLESS

g) END DIAPHRAGMS ARE REQUIRED AT THE ENDS OF GIRDERS TO SUPPORT THE EDGE OF DECK AND THE EXPANSION JOINTS.

OF PROJECT DELIVERY, BRIDGE DESIGN AND TECHNOLOGY DIVISION FOR REVIEW PRIOR TO BEGINNING FINAL DESIGN.

f) FOR CASES OF UNUSUALLY COMPLEX FRAMING AND/OR SEVERE GEOMETRY, SUBMIT A PROPOSED FRAMING PLAN TO THE BUREAU

SKEWS LESS THAN 70.

PLACE PIER DIAPHRAGMS PARALLEL TO THE SKEW FOR SKEW ANGLES OF 70 TO 90, OR NORMAL TO THE GIRDER FOR

INTO THE SUPPORT; RESUME PLACEMENT OF CONTIGUOUS RADIAL DIAPHRAGMS IN THE NEXT ADJACENT BAY. GENERALLY

IN THE IMMEDIATE VICINITY OF THE SKEWED SUPPORTS TO OMIT DIAPHRAGMS THAT WOULD OTHERWISE FRAME DIRECTLY

e) WHEN DIAPHRAGMS ARE PLACED RADIAL TO THE GIRDER IN CURVED AND/OR SKEWED BRIDGES, IT MAY BE ADVANTAGEOUS

GIRDERS AND IN CONTIGUOUS LINES.

d) FOR CURVED GIRDER BRIDGES WITH SKEWED SUPPORTS, GENERALLY PLACE INTERMEDIATE DIAPHRAGMS RADIAL TO THE

AND IN CONTIGUOUS LINES.

c) FOR CURVED GIRDER BRIDGES WITH RADIAL SUPPORTS, PLACE INTERMEDIATE AND PIER DIAPHRAGMS RADIAL TO THE GIRDERS

ORIENT CROSS FRAMES PARALLEL TO THE SKEW ANGLES OF 70 TO 90, OR NORMAL TO THE GIRDER FO