1. 1 PennDOT Truss Gusset Plate Analysis and Ratings Spreadsheet Overview Karim Naji Assistant Structural Engineer FHWA PA Division karim.naji@fhwa.dot.gov 717- 221- 4541 karim.naji@fhwa.dot.gov FHWA Gusset Plate Webinar Series September 24, 2009

2. 2 Developed by PennDOT Bridge Quality Assurance Division Programmed with Visual Basic Application Code First version was released in October 2008 v1.01 is the current version ( General Instructions have not been revised ) Imports member forces from BAR 7 output files Determines member angles using BAR 7 Truss Geometry Table Internally computes Chord Reduction Ratios based on inputted splice plate information Runs three loading cases to determine governing operating ratings for both LFR and ASR methodology Introduction

3. 3 Specifications FHWA Load Rating Guidance and Examples For Bolted and Riveted Gusset Plates in Truss Bridges, February 2009 AASHTO Standard Specifications for Highway Bridges, 17th Ed. AISC Manual of Steel Construction - ASD, 9th Ed. Guide Specifications for Strength Design of Truss Bridges, 1985 AASHTO Manual for Condition Evaluation of Bridges, 2nd Ed., 1994 with interims

4. 4 PennDOT Assumptions Bearing on fasteners at joint is not investigated, only bearing on connected material ( plates ) Slip-critical connections are assumed for all joints Member forces are distributed equally among all fasteners Effective length factor, K, is taken as 2.0 if the gusset plate analysis shows plate has yielded due to shear on the horizontal section; otherwise, 1.2 Horizontal Section

5. 5 For joints with no diagonal members framing in (i.e., post and hanger locations): Chord members are continuous through these joints; therefore, member forces do not transfer to gusset plates and mainly carried by chord members Chord members are continuous through these joints; therefore, member forces do not transfer to gusset plates and mainly carried by chord members If splice plates connect two chord members at these locations, splice plates take majority of loading; therefore, member forces carried by gusset pales are small If splice plates connect two chord members at these locations, splice plates take majority of loading; therefore, member forces carried by gusset pales are small The spreadsheet investigates only the horizontal section for joints without diagonals. Shear at vertical sections assumed to be small. Especially at the supports, may not be true and recommend manual check if vertical shear in plate is present The spreadsheet investigates only the horizontal section for joints without diagonals. Shear at vertical sections assumed to be small. Especially at the supports, may not be true and recommend manual check if vertical shear in plate is present Tensile strength of gusset plate, Fu, is 1.4 Fy as default value when is not entered

6. 6 Method of Solution

7. 7 PennDOT SOL 431-09-02

8. 8 General Instructions

9. 9 Figures

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14. 14 Information Needed Existing plans and shop drawings including any rehabs or retrofits Member dimensions Member dimensions Plate sizes and strengths Plate sizes and strengths Fastener spacing, shear capacities and diameters Fastener spacing, shear capacities and diameters Inspection findings (section loss of gusset plate and number of missing or failed fasteners) D.L. & L.L.+I member forces (maximum or concurrent)

15. 15 Shop Drawings

16. 16 Inspection Findings PennDOT SOL 431-09-02, Page IE 03B-2

17. 17 BAR 7 Output Files

18. 18 Spreadsheet Overview TabsInputSummary Shear A-A Shear B-B Shear C-C Ten. & Comp. Block Shear Connections

19. 19 INPUT

20. 20 Step 1:Open The Spreadsheet Click Enable Macros.

21. 21 Click Continue

22. 22

23. 23 Step 2:Import BAR 7 Output Data Click Import Menu Click Import Menu Click BAR 7 Output Data Click BAR 7 Output Data Select a case Select a case

24. 24 Step 2:Import BAR 7 Output Data Click OK

25. 25 Step 3: Locate BAR 7 Output File Click Save

26. 26 Step 3: Locate BAR 7 Output File Click OK

27. 27 Step 3: Locate BAR 7 Output File

28. 28 Step 4: Input Remaining Information Complete blue fields

29. 29 Step 4: Input Remaining Information Yellow Columns – Plate Data Gusset plate location Plate yield stress in ksi Plate thickness in inches h A, h B, h C, e A, e B, e C, b – See Figures Fastener data

30. 30 Step 4: Input Remaining Information

31. 31 Step 4: Input Remaining Information Green Columns – Member Data Green Columns – Member Data W # – Distance between outermost rows of fasteners L # – Distance between first and last row of fasteners N t# – Number of fasteners across width N l# – Number of fasteners along length L C# – Unsupported length

32. 32 Step 4: Input Remaining Information

33. 33 Step 5: Run Analysis Click Run Click Run Click on Perform Analysis and Ratings on Current Click on Perform Analysis and Ratings on Current Case to run the input tab case Case to run the input tab case Or Or Click on Perform Analysis to Obtain Governing Click on Perform Analysis to Obtain Governing Operating Ratings to run the three loading cases Operating Ratings to run the three loading cases and display the governing ratings and display the governing ratings

34. 34 Step 5: Run Analysis

35. 35 OUTPUT

36. 36 Page 9 of Instructions

37. 37 Page 10 of Instructions

38. 38 Step 1:Review Summary Tab Scroll to far right columns (Governing Operating Ratings) Scroll to far right columns (Governing Operating Ratings) Verify ratings for all gusset plates are above 1.0 Verify ratings for all gusset plates are above 1.0 RED -- No Good GREEN -- OK

39. 39 This Check is Not Required by FHWA Guidance. `

40. 40 Step 2:Resolve “Red” Ratings Complete the following optional input information Complete the following optional input information columns as needed: columns as needed:  Exact total number of fasteners to overwrite the default number of N t# x N l# the default number of N t# x N l#  Splice dimensions to be used for the reduction of chord forces of chord forces  Concurrent member forces if available  Tensile strength, Fu, if know Run Analysis again (Step 5 of Input process) Run Analysis again (Step 5 of Input process)

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44. 44 Step 3: Review Results Scroll to far right columns (Governing Operating Scroll to far right columns (Governing Operating Ratings) Ratings) Verify ratings for all gusset plates are above 1.0 Verify ratings for all gusset plates are above 1.0

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46. 46 Non-BAR 7 Output Step 1:Open blank spreadsheet Step 2:Manually enter all data on Input Tab Step 3:Run the analysis Step 4:Review analysis Step 5:Resolve any ratings below 1.0

47. 47 FHWA Guidance Example vs. PennDOT Gusset Plate Spreadsheet (TGPARv1.01) Page 32 of FHWA Guidance

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52. 52 PennDOT Deck Truss Example

53. 53 BAR 7 Member Forces

54. 54 BAR 7 Truss Geometry Table

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57. 57 Member 5 Compression Zone

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62. 62 File Location PennDOT’s FTP Site: ftp://ftp.dot.state.pa.us/transfer/Bridge/SampleSpreadsheets/FHW A-PennDOT%20Gusset%20Plate%20Webinar_9-24-09/ ftp://ftp.dot.state.pa.us/transfer/Bridge/SampleSpreadsheets/FHW A-PennDOT%20Gusset%20Plate%20Webinar_9-24-09/