STAFAN: A Two-Dimensional Code for Fluid Flow and the Interaction of Fluid Pressure and Stress in Fractured Rock for Repository Performance Assessment

摘要

STAFAN(STress And Flow ANalysis) is a two-dimensional finite element code designed to analyze fluid flow and the interaction of fluid pressure and mechanical stresses in a fractured rock surrounding a nuclear waste repository. The code was developed under the SCEPTER project. This documentation describes the mathematical equations of the physical system being modeled, the numerical techniques utilized, and the code organization and code utility. The STAFAN code takes into account: (a) flow behavior of a deformable fractured system with fracture-porous matrix interactions; (b) the coupling effects of fluid pressure and mechanical stresses in a medium containing discrete joints; and (c) inelastic response of the individual joints of the rock mass subject to the combined fluid pressure and mechanical loading. STAFAN will be used within the NWTS project to develop an understanding of ground-water flow in a host rock surrounding the nuclear waste repository subsystem and to assess the influence of mechanical deformation on flow capacity and velocity field as well as the influence of fluid pressure on the stress field. (ERA citation 08:042449)