Study on FEM Strength Reduction Method for Stability against Sliding at Deep Layer of Foundation for Concrete Dams

The stability safety factor against sliding at deep layer foundation of one gravity dam is analyzed by using the FEM Strengthen Reduction Method (Dawson, E. M., 1999). An evaluating criterion for both single and overall dam is established based on the intensity index of the foundation and weak structural surfaces whose material parameters are reduced through analyzing. For a single dam, the significant displacement change of the feature point at the dam crest is taken as the criterion to define the safety while its corresponding reduction factor regarded as the safety factor (Zhou Guiyun, 2006). Meanwhile, for the overall dam, its evaluating criterion is to find out the plastic zone that is about to run through the foundation (Luan Maotian, 2003), and the safety factor is the corresponding reduction factor of run-through state. The results indicate that the dam is safe under natural condition and safer under the reinforced condition.