Physical Modeling of Reinforced Soil Retaining Walls Under Dynamic Loading Using Shaking Table Experiments

This study investigates the seismic response of reinforced soil retaining walls through reduced-scale 1 g shaking table experiments, with particular emphasis on deformation behavior and pore water pressure generation in saturated sandy soils. Physical models were constructed using Firuzkuh silty sand and extensible fabric reinforcement, considering two soil conditions: an undisturbed loose state and a compacted state with a relative density of 35%. Horizontal dynamic loading with peak acceleration ranging from 1 g to 3 g was applied, while acceleration, displacement, and pore water pressure responses were continuously monitored. The results demonstrate a pronounced depth-dependent pore water pressure response, with deeper soil layers exhibiting higher magnitudes and longer persistence of excess pore pressures. In the undisturbed loose sand, the excess pore water pressure ratio approached unity at depth, indicating near-liquefaction conditions. In contrast, moderate densification significantly reduced pore pressure buildup and promoted partial dissipation during shaking. Reinforcement and compaction were found to effectively limit lateral displacement and settlement, leading to improved seismic performance. The findings highlight the critical roles of soil fabric, density, and reinforcement in controlling deformation and liquefaction susceptibility of reinforced soil retaining walls under seismic loading.