关键词: 尖点突变, 应变软化, 水致弱化, 刚度比, 柔性支挡结构

Abstract: Taking cutting landslide of expansive soils controlled by discontinuities as an example, a simple mechanical model considering water swelling is proposed, which takes the strain-softening and water-softening of slip surface materials under the condition of rainfall into the consideration. Furthermore, the mechanism of the cutting slope of expansive soils is analyzed by catastrophe theory. Many factors trigger landslide, such as moisture content and stiffness ratio. The results show that evolution process of landslide is resulted from internal and external factors, and the cause of rainfall resulting in softening-swelling of discontinuities belongs to the external triggering factors. The water controlling should be taken into consideration in the process of reinforcing cutting slope.

Key words: cusp catastrophe , strain-softening , water-softening , stiffness ratio , flexible retaining structure ;