Seismic Response of Reinforced Retaining Walls with Saturated Calcareous Sand Backfill Subjected to Acid Rain Erosion

The seismic performance of honeycomb concrete canvas geocell-reinforced retaining walls with saturated calcareous sand backfill was investigated. Four different shaking table test models were constructed to determine the effect of reinforcement, saturation, and acid rain erosion. Before the shaking table tests, cyclic simple shear tests were conducted to investigate the effect of acid rain on the seismic response of calcareous sand. Then, considering the effects of input accelerations, the seismic response of the retaining walls was examined, along with the acceleration, lateral displacement ratio, lateral acceleration-displacement, dynamic modulus, and excess pore-water pressure. The results indicate that the acid rain erosion reduces the shear modulus of the calcareous sand, which causes larger deformations than those in normal sand in tests. With the accumulation of pore-water pressure under seismic loads the softening response of soil gets significant, and the soil damping increases that restricts the development of the acceleration amplification. The deformation in the reinforced saturated model is larger than the reinforced dry model, and the saturation conditions significantly reduce the reinforcement coefficient and modulus of sand.