State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China;
State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China;
Changjiang Institute of Survey Planning Design and Research Wuhan 430010 China;
State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China;
slope; stability; multi-grid method; nonlinear; finite element method;