Repair Strategies for Bridge Abutment Damage Caused by Thermal Movements: A Finite Element Study

This paper presents a comprehensive Finite Element Analysis (FEA) focused on understanding the structural implications of having integral abutments on the I-635 bridges in Kansas City, KS. The bridges consisted of three spans and continuous steel plate girders, with one abutment being integral while the other was non-integral. The inspection reports revealed severe damage linked to excessive thermal movements at the non-integral abutment. The Kansas Department of Transportation (KDOT) proposed making it integral, prompting an FEA investigation to evaluate the effect on the substructure and the superstructure of the bridge. A 2D finite element model of one of the bridges was created using LARSA 4D version 8.00r8000. The model encompassed the bridges' superstructure, abutments, piers, pile foundations, and soil-structure interaction, simulating various load conditions, including dead, live, braking, and thermal loads. Key findings reveal that thermal loads could induce significant negative moments in the superstructure, potentially leading to cracking if both abutments were fixed. While concrete abutment caps showed manageable stress levels, the stress in piles at the abutment location significantly exceeded the yield strength, highlighting thermal loads as a primary concern. These findings are important for future bridge design and retrofitting practices, improving the resilience and longevity of infrastructure. Moreover, the use of FEA provides a robust methodology for evaluating proposed solutions, demonstrating its effectiveness in analyzing complex structural issues.