Use of Digital Imaging for Capturing the Soil Collapse Mechanism Behind Abutments of Integral Bridges

Integral abutment bridges (IABs) offer numerous advantages, including increased resilience and reduced construction and life time maintenance costs, thus making them popular in the transportation industry. Nevertheless, the lack of expansion joints in IABs leads to challenges in thermal load transfer that impact short- and long-term behaviors of IABs. This study explores complex soil-structure interaction behind IABs abutments by testing a downscaled model of the existing integral bridge subjected to 100 cycles of thermal loading and using digital imaging correlation (DIC), a technique originating in fluid mechanics, to capture the evolution of the soil collapse mechanism responsible for the development of bridge approach settlement. Additional measurements show that the rate of collapse gradually decreases with increasing number of load cycles. The results highlight the intricate nature of soil-structure interaction and offer insights into the challenges posed by cyclic movements. The research contributes to advancing the knowledge of thermally induced soil-structure interaction in IABs through emphasizing the relevance of the underlying granular soil collapse for devising engineering solutions for improved performance of IABs.