Stability Analysis Of Bedding Slope Under Non-stationary Earthquake Action

Landslides induced by earthquakes are destructive and harmful.The stability of slopes under earthquakes has become an important issue in geotechnical engineering.There are many uncertain factors in the slope stability analysis under the action of earthquakes,such as the non-stationary random properties of seismic actions and the randomness of slope material parameters.These factors are rarely considered by the traditional method of slope stability analysis,which is not conducive to the safety of engineering evaluation.In this thesis,the bedding slope is taken as the research object,comprehensively considers the non-stationary random characteristics of the earthquake,the randomness of the slope strength parameter and the nonlinearity of the mechanical parameters.In this thesis,the pseudo excitation method and stepwise integration method and the time history analysis method of slope stability are applied to analyze the stability of bedding slope under seismic action,which has important theoretical and practical significance.The main work of this thesis is as follows:(1)Based on the randomness of the slope strength parameters and the dynamic characteristics of the earthquake,the thesis establish a time history analysis method for the stability of the slope under earthquakes.And the time history of dynamic safety factor and the time history of the dynamic reliability of the slope are analyzed.On this basis,a comprehensive evaluation method for the slope overall stability was established by using the minimum average safety factor and the average large failure probability as joint evaluation indicators.The analysis shows that,compared with the traditional quasi-static method,the calculation results of the time-history analysis method can reflect the dynamic process of the stability of the slope under the action of the earthquake,and the calculation result is more reasonable and reliable.Compared with the traditional evaluation method relying on a single safety factor,the comprehensive evaluation method of the slope stability established in this thesis can more comprehensively evaluate the overall stability of the slope,which has a good reference value for the evaluation of slope stability.(2)For the non-stationary random properties of earthquakes and the non-linearity of the mechanical parameters of the slope structural plane,a method of solving the non-stationary dynamic response of the bedding slope is established by using virtual excitation method and step-by-step integration method.The analysis shows that the method of solving the non-stationary dynamic response of the bedding slope for bedding slope established in this thesis can fully consider the statistical characteristics of earthquake occurrence,and has high calculation efficiency and calculation accuracy.(3)Based on the non-stationary seismic dynamic response calculation method and the time-history analysis method of slope stability,this thesis analyzes the time-history of safety factor and dynamic reliability of the bedding slope under non-stationary earthquakes.The comprehensive evaluation method was used to evaluate the stability of bedding slope under non-stationary earthquakes.The analysis shows that,compared with the traditional methods,the method for stability analysis of bedding slopes under the non-stationary seismic action established in this thesis can more accurately reflect the most unfavorable conditions of the slope under the action of earthquakes,and the results are more safety.(4)Using this thesis' s method,the influences of seismic intensity,strength parameters and geometry on the stability of the bedding slope under earthquake are analyzed,which further validates the rationality and practicality of the proposed method.