Seismic performances of the wrapped retaining wall backfilled with polypropylene fiber reinforced rubber-sand mixture

In this study, a fiber-reinforced rubber-sand mixture (FRRSM) was produced by adding random distribution reinforcement of polypropylene fiber recycled from waste plastic, which can strengthen the RSM. The mechanical parameters of FRRSM were tested using indoor experiments. Moreover, the seismic behavior of a wrapped reinforced earth retaining wall backfilled with FRRSM was investigated using the finite element method. First, by comparing the model test results, the accuracy of the nonlinear finite element analysis method, which simulated the earthquake response of a retaining wall well, was verified. Subsequently, the soil used in the model test was replaced with FRRSM, and the facing displacement, vertical settlement, and acceleration response of the retaining wall were analyzed. The results indicate that the seismic performance of the retaining wall was significantly enhanced with an increase in the fiber content (F_C) of the FRRSM. According to the present research, the optimal mixture ratio that can ensure the seismic performance of FRRSM-RW is 10% rubber and 1.5% fiber, that is, R_C = 10% and F_C = 1.5%.