Rock Slope Stability and Stabilization Analysis Using the Coupled DDA and FEM Method: NDDA Approach

Nodal variable-based discontinuous deformation analysis (NDDA), which couples the finite-element method (FEM) mesh inside a discontinuous deformation analysis (DDA) block, aims to improve the stress accuracy and the contact efficiency of the standard DDA method. This article investigates the performance of the NDDA method for slope stability problems. Because the NDDA model considers the entire block kinematics, the assumption on interslice forces among the blocks is no longer necessary. Therefore, the strain/displacement compatibility can be automatically satisfied. The comparison study shows that the factors of safety (FOSs) obtained by the NDDA method are different from those provided by the Sarma method. More intrinsic information, including the distribution pattern of the normal force along the potential slip surface, the distribution pattern of the interslice normal forces, and the ratio between of the interslice shear and normal forces, can be obtained from the NDDA simulation. However, to secure the potentially unstable block, a numerical rock bolt model is introduced into the NDDA framework to simulate the interactive mechanism between the rock mass and the reinforcement. The simulation result shows that the proposed rock bolt system is effective in stabilizing the slope in designed cases.