Abstract
The large strain behavior of materials is significant in various applications in geomechanics. This paper presents the formulation of a finite element model that implements material and geometric nonlinearities, as well as coupling with fluid flow through the porous medium. The model is applied on axisymmetric problems that are common in tunnels or boreholes. The material is assumed to be pressure dependent elastoplastic. Results are presented for a borehole under in situ isotropic stress. A large stress and pore pressure is applied to test the response in the large strain domain and the solution is compared with that predicted by small strain theory. The results demonstrate that large strain analysis provides a more realistic response above a certain strain.