Full-Scale Testing of Geosynthetic-Reinforced, Soil-Integrated Bridge System

This paper focuses on the preliminary results of static load tests that were conducted on a geosynthetic-reinforced, soil-integrated bridge system (GRS-IBS) in Louisiana. Sixteen loading tests that used two fully loaded trucks were conducted on the instrumented GRS-IBS bridge. The bridge was surcharge loaded to stress levels well in excess of working load conditions. To evaluate the performance of the GRS-IBS abutment under different load tests, various types of instrumentation were installed; these included shape accelerated arrays, pressure cells, strain gauges, piezometers, and thermocouples. The primary measurements were the horizontal deformations near the front wall, vertical deformation of the GRS abutment, distribution of stresses in the GRS abutments and below the reinforced soil foundation, and distribution of strains along the geosynthetic reinforcements. Measurements from the instrumentation provided information needed to verify design factors and parameters for the GRS-IBS abutment. The bridge settlement and lateral movement of the facing wall were within the serviceability level; this result demonstrated excellent load-carrying capacity of the GRS abutment. The locus of maximum strains in the abutment varied by the surcharge load and did not correspond to the (45 + ϕ/2) line, especially when the surcharge load was placed at the bridge. The results of the load test revealed that the GRS-IBS bridge responses to the load tests were well within the serviceability limits, and the overall performance of the GRS-IBS was within acceptable tolerance in terms of measured strains, stresses, settlements, and deformations.