Physical Modeling of Temperature Influence on Performance of Geogrid-Reinforced Retaining Walls Considering Backfill Type Effect

摘要

Field measurements show that the seasonal change of the ambient temperature has a significant effect on the performance of geogrid-reinforced retaining (GRR) walls. To investigate the effect of the ambient temperature change on the temperature field inside the GRR walls and the mechanical behaviors of the GRR walls, two physical model tests were conducted using a custom-made model test box. The test box was encased within a temperature-controlled tank to simulate the ambient temperature change and thus to investigate the performance of the GRR walls under the seasonal ambient temperature change. Two types of backfill material, sand and clay, were used in the physical model tests to consider the backfill type effect. Settlement at the top surface, lateral deformation of facing panels, vertical and lateral earth pressures, and geogrid strains were monitored to understand the variation of mechanical performance of the GRR walls with the ambient temperature change. Test results demonstrated that: (1) the ambient temperature has a more significant influence on the temperature field inside the GRR model wall backfilled with sand than that inside the GRR model wall backfilled with clay; (2) under a low ambient temperature of -15 degrees C, the temperature near both the top surface and facing panels decreased to below the freezing point and the vertical frost depth of the model GRR wall backfilled with sand was greater than that of the GRR model wall backfilled with clay; and (3) the measurements indicate that the ambient temperature has a more significant effect on the mechanical performance of the GRR model wall backfilled with clay than that of the wall backfilled with sand, especially under low ambient temperature (i.e., -5 degrees C to -15 degrees C).