Fatigue Repair of the Arkansas River Bridge.pdfVIP

1 Fatigue Repair of the Arkansas River Bridge Y. Zhao1, K. W. M. Roddis2, G. Ramirez 3, J. P. Jones 4 1 Yuan Zhao, Ph.D., P.E., Bridge Design Engineer, Texas Department of Transportation, Bridge Division, (512) 416-2632, yuan.zhao@txdot.gov. Formerly, Doctoral Candidate, University of Kansas. 2 W. M. Kim Roddis, Ph.D., P.E., Professor and Chair, Department of Civil and Environmental Engineering, The George Washington University, (202) 994-4901, roddis@gwu.edu. Formerly, Professor, University of Kansas. 3 Guillermo Ramirez, Ph.D., P.E., Assistant Professor, Department of Civil Engineering, The University of Texas at Arlington, (817) 272-2683, willy@uta.edu. Formerly, Assistant Professor, University of Kansas. 4 John Patrick Jones, P.E., Manuals, Modeling and Policy Engineer, Kansas Department of Transportation, Bureau of Design, State Bridge Office, (785) 368- 7175, jjones@ksdot.org. BACKGROUND Since the Kansas Department of Transportation (KDOT) started its fracture critical bridge inspection program around the mid-1980s, many welded steel bridge details at the diaphragm (or floorbeam) to girder connections were found to have developed fatigue cracks, often due to the cause of out-of-plane distortion. While proper fatigue design philosophy has been developed and incorporated into the current AASHTO bridge design specifications, repair of existing bridges with fatigue cracking remains a challenge to the bridge engineering community, especially when the repair details happen to reside in locations with geometrical complexity, or when cracking is compounded by corrosion or impact damage. Beginning 1996, a series of research studies were performed through the collaborative effort between the KDOT State Bridge Office and the University of Kansas (KU). Five candidate structures were selected to examine the overall fatigue problem experienced by the KDOT steel bridges, using state-of-art finite element (FE) modeling technique. Two of