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1 PDH · about 60 minutes · Course no. BR-F01 · Instructor: Michael Craig, PE
Michael Craig, PE is Senior Vice President and Southeast Director at Strinteg Corporation, leading bridge inspection and structural engineering across eight states and Puerto Rico. In 27+ years he has inspected over 4,000 structures and completed 3,000+ load ratings and 160+ load tests. He has managed repair and preservation design for complex bridges, including cable-stayed bridges. He holds PE licenses in twelve states, DC and Puerto Rico, SPRAT Level 1, and FAA Part 107 credentials.
Fatigue cracking is the most common form of structural damage found in steel highway bridges, and the way an engineer responds to a crack depends on understanding why it formed. This course explains load-induced fatigue and the AASHTO LRFD nominal-stress approach with its eight detail categories (A through E′), the Fatigue I and Fatigue II limit states, distortion-induced fatigue in web gaps and connection angles, how cracks are found, and the repair and retrofit methods documented by FHWA. It draws on FHWA's Manual for Repair and Retrofit of Fatigue Cracks in Steel Bridges (FHWA-IF-13-020, Dexter and Ocel, 2013) and Chapter 12, Design for Fatigue, of the Steel Bridge Design Handbook (NSBA/AISC, February 2022 edition, updated to the 9th Edition AASHTO LRFD Bridge Design Specifications). Values quoted from AASHTO tables are reproduced as that handbook states them; confirm them against the edition your agency has adopted.