基于非线性有限元的高拱坝坝肩稳定性分析-研究生论坛

处于复杂地质条件下的拱坝，坝肩岩体稳定性问题是其发生事故的重要原因之一。某水电站拱坝右坝肩发育有靠近坝体的蚀变集中带及沿该集中带的多条断层，左坝肩在坝肩槽不同高程有多条断层出露，地形地质复杂。为了正确合理地研究其坝肩岩体的稳定特性，根据水电站坝址区地形地质条件，充分考虑拱坝左右坝肩的主要断层及蚀变带等不利地质构造，建立三维有限元模型，模拟拱坝及坝区岩体在正常运行及温降工况下的应力场，采用点安全系数法分析坝肩岩体在加固和未加固的情况下的稳定性，并运用综合强度储备法评价坝肩的极限承载能力。研究结果表明，坝肩岩体点安全系数均处于合理范围内且相对较高，综合安全系数相对较大，说明坝基加固措施合理有效，坝肩具有较强的承载能力。

Analysis of abutment stability for high arch dam Based on Nonlinear FEM

The dam abutment rock mass stability is one of the important reasons for accidents of arch dams that are under complicated geological conditions. A hydropower arch dam located in some area of complicated topographic and geological conditions, there are concentrated alteration zones developed closing to the right dam abutment, and along these zones several faults developed. Apart from that, on the different heights of its left abutment, some faults developed as well. In order to study the stability of the arch dam abutment rock mass, a 3-dimension finite element model is built based on the topography and geology of the dam site with taking into full account of the adverse geologic structure factors such as the abutment''s practical geological, the major faults and the alteration zone. 3-dimension nonlinear finite element method is applied to simulate the stress filed of arch dam and rock mass in dam site under normal operating conditions with temperature drop. Whether the rock mass is reinforced or not, the stability of dam abutment is analysed by point safety factor method, and the abutment ultimate bearing capacity is simulated by synthesis method. The results show that the value of point safety factor of abutment rock is within a reasonable range and relatively high, synthesis safety factor is relatively large, suggesting that arch dam body is reasonable, reinforcement measures are rational and effective, and the abutment ultimate bearing capacity is relatively strong.