Experimental and Analytical Study on the Progressive Failure of Cut Slopes

摘要

Cut slopes in mudstone and stiff clay can fail from a few days to many years after the excavation. Some cut slopes in London clay abruptly collapsed after several decades. This time-dependent failure phenomenon, referred to as progressive failure, is attributed to a decrease with time in the shear strength of the materials. In addition, strain softening also promotes progressive failure. In the present paper, centrifuge model tests are conducted using a model ground made of a plaster and clay mixture, which shows strain-hardening and strain-softening behavior, in order to clarify the mechanism of the progressive failure of cut slopes. Then, a finite element analysis of a soil-water coupled problem is conducted using an elasto-plastic constitutive model with strain softening. By comparing the experimental and the analytical results, the progressive failure mechanism of cut slopes is discussed.