Field behavior of a GRS bridge approach retaining wall on highly compressible foundation soils

Abstract

To reveal the behavior of geosynthetic-reinforced soil (GRS) bridge approach retaining walls on highly compressible foundation soils, in this study, a GRS bridge approach adjacent to the Yangtze River was monitored for approximately 3 years during construction and post-construction. The settlement of the GRS bridge approach, the vertical earth pressure at the base of the backfill soil, and the reinforcement deformation were monitored. The monitoring points were arranged on the left and right sides of a cross-section and a longitudinal section at the mid-span. The results showed that the settlement of the GRS bridge approach was large and uneven, and the settlement rates were influenced by the water level of the Yangtze River. Due to the large and differential settlement, the distributions of the vertical earth pressure and geogrid reinforcement strain for a retaining wall constructed on highly compressible foundation soils were different from those for a retaining wall constructed on stable foundation soils. The overall GRS bridge approach performed well with large settlements, with only some minor structural problems in the facing of the retaining wall. This indicated that the flexible GRS bridge approach was a good choice when the retaining wall was constructed on highly compressible foundation soils.