Slope Stability Analysis Of High Earth-rockfill Dams Based On ABAQUS

Slope stability analysis is a key issue in rock-soil mechanics. Recent years, FEM strength reductions method has become an important measure to analyze the high dam, due to its obvious advantages, such as no need to define sliding surface and accurate compute the internal force. Based on general software ABAQUS, and FEM strength reduction method, the following work has been done on the slope stability of high earth-rock dams:1. defining the reduction coefficient as field variable in ABAQUS, can reduces the FEM strength reduction to one step, and saves a lot of time and makes the compute results more accurate. Via analyzing the results of slope stability, the three criteria of FEM strength reduction method were discussed:judging by numerical calculation convergence criteria, the slope safety factor is larger; judging by run-through of plastic zone of slope soil and displacement inflection point method, which can reflect the process of yield failure of slope, the safety factor is more or less of the safety factor derived from conventional limit equilibrium method.2. analyzing the safety factors of standard slope of face rockfill dam which were common used in hydropower projects by FEM strength reduction method, and compared the results with the results of the earth-rock special design program STAB, it can be found that when correct parameters were chosen, the results derived from linear have bite force strength index and nonlinear intensity index are very close, and the critical slip surface cracks of both methods also match.3. in order to check the safety factors of both the dam slopes of upstream and downstream respectively by ABAQUS, several treatments have been done:when computing the upstream dam slope, increased the shear strength parameters of rockfill of downstream, so that the upstream dam slope will fail before the downstream dam; of course it's the same in reverse. Considering the horizontal seismic load, divided the dam model into several layers, and took the median line value of trapezoidal distribution area of each layer to simulate the horizontal earthquake inertia force. For dam under stable seepage period, the analysis of unsaturated soil water flow can be conducted first, and obtain the stress distribution of dam under water seepage, and then took this stress field as the initial stress field of strength reduction analysis steps to analyze the stability both upstream and downstream dam. 4. analyzed the six different working conditions of core rockfill dam of Shuangjiangkou by both FEM strength reduction method and limit equilibrium method, and compared the results, provided scientific proofs for engineering practice.