A Study of High Slope Stability of Yangfanggou Dam Site

The engineering geological conditions of the slope of Yangfanggou dam site are firstly analyzed. From the perspective of valley evolvement, the distinct element model of Yangfanggou river valley is established based on the investigated geological data. On the basis of the model established, the results of stress in slope are calculated by introducing the software of UDEC. According to simulation results, the basic law of stress and plastic zone is concluded as follows: Stress field appears as four sub zones including the original zone of stress, the relaxation zone of stress, the concentration zone and the transition zone of stress; the horizontal depth of the plastic zone calculated is about 10 m∼30 m, and the developing depth in left bank slope is larger than depth in right bank slope. Simulation results are consistent with the actual geological conditions at the dam site. The coefficient of slope stability is calculated by adopting the method of strength reduction, and the value is 1.89. There is a sliding block at the right bank slope in the limit state.