ABSTRACT
Slope stability analysis is traditionally performed using limit equilibrium methods that have remained essentially unchanged for decades. While giving generally conservative estimates of safety factors, the traditional methods give no indication of progressive failure or how the yield spreads. This paper will describe some finite element analyses of slope stability using a relatively simple elasto-plastic, Mohr-Coulomb soil model. Within the finite element model however, gravity can be applied in different ways. For example, a “gravity turn on” procedure can be used where an initially weightless slope is instantaneoulsy subjected to self-weight loads. Alternatively, the slope can be “built-up” using an embanking procedure that creates the mesh one lift at a time, or similarly, by an excavation procedure. The different loading strategies and their influence on yeilding of the slope is highlighted in the paper through the use of contour plots of the failure criterion, which indicate the spread of yield within the slope and hence the location and shape of the potential failure surface. The influence of the loading strategies and dilation on the ultimate slope factor of safety is also examined.
