ABSTRACT
The effect of the different loading paths associated with excavation and fill placement for different initial stress conditions on both the failure mechanism and the safety factor of a particular slope is investigated. Both associative and non-associative Mohr Coulomb laws are used. The analyses are all carried out in two stages: First the slope is formed either by excavation from or placement upon originally level ground, and then the shear strength is reduced until failure occurs. The procedure for the second stage is novel in that it uses the collapse settlement method pioneered by the Author (in a NUMOG III paper) to simulate the strength reduction. 12 combinations of parameters are studied. The results show both the deformation patterns and the general stress state close to failure to vary considerably. In all cases, however, the quite different stress paths for two points close to the final failure surfaces end up at almost the same point in stress space. The finite element safety factors were close to but, surprisingly, slightly greater than the limit equilibrium method value.
