Finite element analyses of computational effects with of different shear strength expressions for layered rock mass

In order to investigate the effects of different anisotropic shearing strength expressions on numerical computation results, the two-dimensional elastoplastic finite element analysis were carried out for an assumed rectangular underground cave in a layered rock mass for three cases, in which the empirical formulae for internal friction coefficient and cohesion of material which change with directions suggested by the first author and S. Pietruszczak were applied respectively. The stresses, displacements and plastic zones in the surrounding rock mass are compared. The results show: the computational accuracy of using the empirical expressions established by the first author matches basically with that of using the first-order approximations given by Pietruszczak; but there is a comparatively obvious difference between the computational accuracies of using author's empirical expressions and Pietruszczak's 2nd order approximations.