Abstract

In this paper, the slope failure in sensitive clays is studied numerically using the particle finite element method which is a novel approach capable of tackling extreme deformation problems. The sensitive clay is described using an elastoviscoplastic model with strain softening. This model can be considered a mixture of the Tresca model with strain softening and the classical Bingham model. The former is used to capture the solid-like behaviour, for example when the clay is intact, whereas the latter is to describe the semi-fluid behaviour of the fully remolded clay. The complete process of the collapse of a sensitive clay deposit is captured successfully and the widely-observed retrogressive failure mode is reproduced. The mechanism behind the failure is also discovered.

Abstract

This paper presents a detailed numerical study of the retrogressive failure of

landslides in sensitive clays. The dynamic modelling of the landslides is carried

out using a novel continuum approach, the particle finite element method,

complemented with an elastoviscoplastic constitutive model. The multiwedge

failure mode in the collapse is captured successfully, and the multiple retrogressive

failures that have been widely observed in landslides in sensitive clays

are reproduced with the failure mechanism, the kinematics, and the deposition

being discussed in detail. Special attention has been paid to the role of the clay

sensitivity on each retrogressive failure as well as on the final retrogression distance

and the final run‐ out distance via parametric studies. Moreover, the

effects of the viscosity of sensitive clays on the failure are also investigated

for different clay sensitivities.