Kinematic stability analysis of nonuniform soil slopes under pore-pressure effects based on central difference discretization technique

This paper proposes an efficient algorithm in a discretization-based kinematic approach (DKA) to investigate the stability of non-uniform soil slopes in the presence of pore water pressure. In response to the problems of high dependency on discretization interval and low computational accuracy involved in the initial DKA based on a forward difference scheme (DKA-FD), a central difference ‘point-to-point’ method is developed to generate discretized failure surface. Based on this, an improved DKA with a central difference algorithm (DKA-CD) is formulated, with slope stability solutions obtained in terms of stability number, safety factor and critical failure surface. The research findings demonstrate that slope failure at limit state gradually shifts from below-toe and deep-toe modes to shallow-toe mode with the increase of slope angle and soil friction angle. The transition on slope failure pattern becomes more obvious with decreased pore pressure and increment in non-uniform gradient for soil friction angle.