Shaking Table Tests on Sliding Displacements of Loess Slope under Coupling Effect of Rainfall and Earthquake

摘要

Shaking table tests were performed to investigate whether the coupling effect of rainfall and earthquake induces the loess slope instability. The loess slope model was made by using the similarity ratio based on a real slope. Artificial rainfall was carried out, and then seismic waves were loaded step by step to adopt a large shaking table of 4?6?m. The displacement in x, y, and z directions and absolute displacement of loess slope (ux, uy, uz, and ua) were measured to use the XTDIC displacement test system in 50?s when the seismic waves at peak acceleration were loaded to 600?gal, 700?gal, 800?gal, 976?gal, and 1300?gal, respectively. The results showed that the acceleration of one point was much larger than the other. ua occurred when seismic waves were loaded to 700?gal, and uamax was obtained when seismic waves were loaded to 1300?gal finally. The umax would reach in 20～25?s, which was the period of amplitude peak. The theoretical value was larger than the test value for the critical seismic acceleration coefficient. Loess liquefaction appeared along the slope top under 976?gal loading condition. The change of displacement in y direction is the main reason for the curve trajectory of the sliding block, and the displacement differences of adjacent measuring points are the main reason for the formation of the sliding block. This study can provide a theoretical basis for loess slope design and risk management.