Developing a new slice method for slope displacement analyses

Abstract

Conventional slice methods of slope stability use a constant value of safety factor along the entire failure surface, providing no information of displacements and possible variations about safety margins for the analyzed slope. Therefore, it is of practical significance to extend the force-based slice method into a displacement-based one to provide useful information about shear displacements and associated safety margins along the potential failure surface. This study extends Janbu's Generalized Procedure of Slices (GPS) by supplementing force and moment equilibrium and the Mohr–Coulomb failure criterion, which are employed in the Janbu's GPS, with additional criteria regarding slice displacement compatibility and non-linear stress–displacement relationships represented by a hyperbolic soil model. The extended displacement-based slice method constitutes a statically determinate system which is capable of generating local stress- and displacement-based safety factors along a potential failure surface. The principles and procedures proposed here can also be applied to other slice methods, regardless of their accuracy. Results of a case study show that the observed slope displacement induced by a ground table rise during a rainstorm event can be well simulated using the proposed method. More case studies into various mechanisms of slope displacements will be performed in the future to validate the proposed method for practical engineering applications.