FINITE ELEMENT ANALYSIS OF ROCK SLOPES WITH INSITU STRESSES

Abstract

The stability of rock slopes is of great concern to the geotechnical engineer in a variety of projects such as open pit mining, deep spillway cuts, reservoir slopes, or excavations for the highways. The problem of rock slope stability is examined thoroughly, regarding the variation of in-situ stress parameter, K with depth, orientation of bedding planes, rock slope angles, and rock slope heights. Two-dimensional finite element method is used for solving the problem of rock slope stability with the inclusion of infinite elements to represent the far field behaviour of rock mass. The displacement vectors and stress contours for these cases have been produced for studying the slope angle effect, slope height effect, and the effect of orientation of bedding planes. In all these above cases, K is varied with depth. Displacement vectors are presented for a constant value of K also. The displacements present the initial movement of the material, which remains stable, unless tensile stresses are developed. The tensile stress zone and maximum tensile stress depend on the rock slope angles, height of rock slopes as well as the orientation of bedding planes. The depth of tension crack depends on the rock slope angle and height of the slope but independent of the orientation of bedding planes, when K is varied with depth. The depth of tension crack depends on K also, when K is constant with depth.