Abstract：In order to analyze the formation mechanism of slope earthquake-induced deformation，combining with the detailed investigation on the earthquake-induced deformation and failure phenomenon caused by Wenchuan earthquake，the comprehensive analysis method，finite element numerical analysis and vibration table simulation experiments are adopted to analyze the earthquake-induced mechanism of single- and double-side slopes. The results show that the earthquake waves will make the stress field of slopes change significantly. The slope body，especially the grade surface，will generate repeatedly tensile and shear actions，of which values and orientations adjust continuously. These actions are significant reasons of slope failure. It is discovered that the shear actions has three representative forms，i.e. first motion tensile and shear acceleration rending effect，repeatedly tensile and shear rending effect，and double-side common shear rending effect. These rending effects have been found in practice. The results can provide references to forecast failure of earthquake-induced slope and reconstruction of powerful foundation after earthquake and hazard-resistant reduction.
