Expansion of bridge girders in summer moves integral bridge abutments toward backfill, causing high lateral earth pressures behind the abutment. Some backfill material slumps downward and toward the abutment when the abutment moves away from the backfill due to bridge girder contraction in winter. Placement of geogrids within the backfill can increase stability of the backfill while placement of compressible inclusions (e.g., Expanded Polystyrene (EPS) foam) can reduce lateral earth pressures behind the abutment caused by bridge girder expansion. In this study, six physical model tests were conducted with 30 abutment top movement cycles due to simulated seasonal temperature changes to study the performance of integral bridge abutments with different mitigation measures. The test results showed that geogrid reinforcements caused higher maximum lateral earth pressures at the same abutment movement, but geogrids with wrap-around facing significantly reduced the backfill surface settlements. The combination of the EPS foam and geogrids could minimize lateral earth pressure increase and backfill settlement. The EPS foam reduced the abutment toe outward movement when the abutment top was pushed against the backfill; however, the mitigation effects by the EPS foam was limited due to its small thickness and relatively high elastic modulus in this study.

夏季桥梁大梁的扩张将整体桥台移向回填土，导致桥台后面的侧向土压力高。由于冬季桥梁梁收缩，当桥台远离回填土时，一些回填材料向下并朝向桥台坍塌。在回填土中放置土工格栅可以增加回填土的稳定性，而放置可压缩夹杂物（例如，发泡聚苯乙烯 (EPS) 泡沫）可以减少桥梁膨胀引起的桥台后侧向土压力。在这项研究中，由于模拟季节性温度变化，对 30 个桥台顶部移动循环进行了六个物理模型测试，以研究具有不同缓解措施的整体桥台的性能。试验结果表明，土工格栅加筋在相同的桥台运动下会产生更高的最大侧向土压力，但具有环绕饰面的土工格栅显着降低了回填表面的沉降。EPS泡沫和土工格栅的组合可以最大限度地减少横向土压力增加和回填沉降。当基台顶部推向回填物时，EPS 泡沫减少了基台脚趾向外移动；然而，在这项研究中，EPS 泡沫的缓解效果有限，因为它的厚度小，弹性模量相对较高。当基台顶部推向回填物时，EPS 泡沫减少了基台脚趾向外移动；然而，在这项研究中，EPS 泡沫的缓解效果有限，因为它的厚度小，弹性模量相对较高。当基台顶部推向回填物时，EPS 泡沫减少了基台脚趾向外移动；然而，在这项研究中，EPS 泡沫的缓解效果有限，因为它的厚度小，弹性模量相对较高。