NUMERICAL MODELING OF THE FLEXURAL DEFORMATION OF FOLIATED ROCK SLOPES

Toppling failure of slopes in a foliated (layered) rock mass occurs es sentially due to tensile breaking of rock columns where there are no c ross-joints to act as the basal planes of blocks. The rock columns und er their self-weight freely bend into the excavation and induce tensil e (bending) stresses. Thus, the knowledge of deflection (bending) of t he rock columns and resulting stresses plays a major role in the stabi lity analysis of such slopes. A continuum model based on the Cosserat theory, which includes the bending (couple) stresses in its formulatio n, has been devised and incorporated into a finite element code. The n umerical results have been compared with the results of centrifuge exp eriments and the comparison shows agreement suggesting that the model is capable of reproducing a complex pattern of load-displacement behav iour as seen in the centrifuge models. The Cosserat model has proven t o be a useful tool for predicting the behaviour of slopes in a foliate d rock mass. The Cosserat model has also been used to verify the exist ence of a limiting equilibrium state in foliated rock slopes as assume d in the Aydan and Kawamoto model. Copyright (C) 1996 Elsevier Science Ltd