Study On The Seismic Stability Of Slope Based On Time History Analysis Method And Finite Element Method

The failure of slope with the action of earthquake depends on the details of ground motion strongly. It is unsuitable to evaluate the anti-slide stability of the slope under seismic load by using the minimum slope stability safety factor that occurs at one moment during the process of earthquake. In this paper, the mean value of safety factor is presented as the evaluating index. The minimum mean value of safety factor and corresponding failure surface in potential failure field are obtained. The time history of earthquake is considered.First, the time history analysis method and finite element method of the seismic stability of slope are introduced.Second, based on these two methods, two new analysis methods of the slope seismic stability that considered the time history of earthquake and the accumulation of slope failure are presented. For the first method, both the corresponding beginning time and minimum mean value of safety factor during each period of time could be obtained in term of searching the minimum mean value of safety factor during some decided periods of time on the safety factor time history curves of each failure surface in potential failure field. And the second method, the earthquake wave is cut into a lot of time steps. Based on searching the minimum safety factor and the most dangerous failure surface of each time step, the period of time that the safety factors less than the allowed value on the safety factor time history curve of each failure surface are found. By comparing the mean values of safety factor during the searching time periods, the minimum mean value of safety factor is obtained and the corresponding time period is the most dangerous period during the earthquake.Finally, apply the excitation with different earthquake waves, the acceleration with different peak values and the slope with different ratios to a high earth-rock dam's stability analysis and which is researched under six special conditions. Followed by comparison and analysis, the parameters' effects on the slope stability under the different conditions are presented. Through the comparison with the traditional slope stability analysis method, the two analysis methods' rationalities and feasibilities are proved.