Simulation of the nonlinear mechanical behaviors of jointed rock masses based on the improved discontinuous deformation and displacement method

摘要

This study further develops the discontinuous deformation and displacement (DDD) method to model the nonlinear deformation and failure behaviors of jointed rock masses. The improved DDD (IDDD) method is then proposed to provide a unified formulation for solving the transformation of rock materials from continuum to discontinuum. By embedding finite elements into model blocks, the deformation ability and stress distribution within blocks are refined, and the fracture of an intact block is permitted. Namely, the rock blocks containing a number of finite elements are deformable and can be broken into several smaller parts during calculation. The edges of damaged elements are new joints and mechanical interaction between neighboring blocks along these new interfaces is therefore allowed. A series of numerical tests are conducted to validate the correctness and effectiveness of the IDDD model in terms of bending deformation, frictional contact, strength characteristics, crack propagation, etc. Meanwhile, the failure mode of a block system and flexural toppling of a jointed rock slope are further analysed. The results are in good agreement with the theoretical analyses, previous studies and experimental data. Overall, the proposed IDDD method is effective and reliable to model the nonlinear mechanical behaviors of jointed rock masses and it has shown particular advantages over the conventional numerical methods.