Study On The Influence Of Pore Water Pressure Variation On The Stability Of Slope Under The Action Of Rainfall And Earthquake

The study of slope stability has always been a research topic that geotechnical engineering is highly concerned.Rainfall and earthquakes are the most important natural factors inducing landslides,and also the most direct causes of landslides.They are also very harmful to people's lives and property.In recent years,it has become a research hotspot to discuss the slope stability by the combined rainfall action of earthquakes.In the existing research,the characteristics of dynamic pore pressure and infiltration are hardly considered.To this end,this paper will study the stability and seepage pore pressure of soil slopes and accumulations under the combined effects of different intensity rainfalls and different levels of earthquakes through theoretical analysis and numerical simulation based on previous studies Law,dynamic pore pressure change law,dynamic response characteristics.The main content and results of this article are as follows:(1)The dynamic pore pressure model is modified based on the energy method,and the slope safety factor formula under rainfall and earthquake action is deduced by using limit equilibrium method.(2)Through numerical simulation,the dynamic pore water pressure and stability of soil slope and accumulation body slope under 12 kinds of rainfall-seismic combined working conditions were studied.The study found that the direction of infiltration of rainwater in the slope of the accumulation body is generally perpendicular to the direction of the slope surface,the pore pressure is distributed in a gradient from the slope surface to the base cladding,and the soil slope is distributed in a gradient along the vertical direction.(3)The numerical simulation results and engineering case analysis verify the pore pressure formula and safety factor formula deduced in this paper.The results show that for soil slopes,the calculation error of the seepage pore pressure formula is within6.96%,the dynamic pore pressure error is within 9.43%,and the safety factor error is within 11.35%;for the accumulation slope,the calculation error of seepage pore pressure is 6.32 Within %,the dynamic pore pressure calculation error is within 9.27%,and the safety factor error is within 8.24%.The formulas in this article can be used to calculate soil slopes and accumulation body slopes,and the results are more accurate when calculating accumulation slopes.(4)Research shows that under the action of rainfall-earthquake,the slope of accumulation body is more prone to sliding failure along the base cladding.The study found that the dynamic pore pressure increased sharply under the action of seismic load.After increasing to a certain value,the dynamic pore pressure showed different fluctuation trends with different positions.