Deformation Responses of a Geosynthetic Reinforced Soil-Integrated Bridge System Under Static Loading and Sensitivity Analysis of Influential Factors Based on the Improved Grey Relational Method

A numerical parametric study is conducted to evaluate the effects of various parameters on the deformation responses of a geosynthetic reinforced soil-integrated bridge system (GRS-IBS) under static load. The investigated parameters include the abutment height, reinforcement spacing, reinforcement length, reinforcement stiffness, bridge load, and backfill internal friction angle. The improved grey relational method is used to investigate the sensitivity of influential factors on the deformation responses of the GRS-IBS. The simulation results indicate that the abutment height, reinforcement spacing, and bridge load have a significant impact on the performance of the GRS-IBS with respect to lateral displacement and settlement, while the effects of reinforcement length, reinforcement stiffness, and backfill internal friction angle on the deformation behavior of the abutment are negligible. Differential settlements between the girder and approach are minimal under all conditions. The potential failure envelope of the GRS-IBS exhibits a "L" shaped configuration where the potential failure surface starts beneath the inner edge of the strip footing, extending vertically downward to half of the wall height and further bifurcating toward the strip footing and the toe of the wall. The results of the improved grey relational analysis show that reinforcement spacing is the most sensitive to the lateral displacement of the GRS-IBS. The abutment height and bridge load are more sensitive to abutment deformation than other influential factors. These three parameters are crucial to the deformation behavior and should be given primary consideration when designing a GRS-IBS.