Influence of Matric Suction on the Stability of Unsaturated Slope

Abstract

Matric suction plays a significant role in the unsaturated slope stability and receives a rising interest in how matric suction affects the unsaturated slope stability. According to the shear strength theories and soil-water characteristic curve of unsaturated soils，matric suction parameters were proposed to study the influences of matric suction on unsaturated slope stability by applying in strain-softening constitutive model and using catastrophe theory as a tool. The results show that the unsaturated slope safety factor depends on the stiffness ratio，the softening coefficient，the suction sensitive factor and the relative displacement ratio. However，when the system reaches the limit equilibrium circumstance，the fundamental factors particularly affecting the unsaturated slope stability are the stiffness ratio of two media and the softening coefficient of the sliding surface，and the further trend between matrix suction and unsaturated slope stability is the same as the changes of the suction impact factor.