CRITICAL MEMBER REMOVAL AND LOAD REDISTRIBUTION OF A DETERIORATED TRUSS BRIDGE
Open Access
- Author:
- Reese, Lynsey
- Graduate Program:
- Civil Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Dr Daniel Linzell, Thesis Advisor/Co-Advisor
Daniel G Linzell, Thesis Advisor/Co-Advisor - Keywords:
- Deterioration
Critical Member Removal
Pratt Truss - Abstract:
- Serious questions surrounding the strength and stability of truss bridges and the adequacy of the aging infrastructure have arisen due to the collapses of the I-35W Bridge in Minneapolis, Minnesota and the Dysart Bridge in Cambria County, Pennsylvania. The behavior of truss bridges when a critical member is removed is at the forefront of research. Being able to understand the load redistribution as well as the global response of deteriorated truss bridges when critical members are removed needs to be fully understood to prevent any further collapses from occurring. A pristine and deteriorated model was created to determine the effects of aging and deterioration on the critical member removal and load redistribution response of a truss bridge. Key information in the analysis was the critical member (assumed to fail when it reached its yield capacity or critical buckling load), the critical load that caused the member to yield, the location of the critical load, and the failure sequence once the critical member was removed from the structure. Eight stacked side-by-side HS-20 trucks caused the pristine model to fail while a loading of seven stacked side-by-side HS-20 trucks caused the deteriorated model to fail. The member failure sequence also was different for the pristine model compared to the deteriorated model. Deterioration and aging was found to have a direct impact on the load redistribution and global failure pattern of the truss bridge.