Study On The Stability Of Spoil Slope Under The Coupling Action Of Rainfall And Earthquake

With the deepening of national infrastructure construction,the number of large geotechnical structures continues to increase,which will inevitably lead to a large number of excavations of earth and stone,resulting in a large number of artificial slope structures such as spoil grounds,dumps and tailings ponds.In order to study the effects of rainfall,earthquakes and rainfall-earthquake coupling on the stability of spoil slopes,this paper takes a large spoil site in a certain area of Yunnan as an example,collects relevant geological survey data of the research site,and obtains relevant parameters of each layer,Query the seismic dynamic response data of the research site,obtain the saturated water content and permeability coefficient of each soil layer through field investigation,indoor and outdoor experiments,analyze the potential instability factors of the spoil slope,and calculate the spoil in the steady state.The soil slope is in a stable state.However,because the research site is located on a medium-to-high intensity seismic zone,and the annual rainfall is basically concentrated in the rainy season,it is very likely to cause instability and landslides on the spoil slope.Therefore,this paper intends to use GeoStudio software to establish rainfall models and earthquakes.The model and the rainfall-seismic coupling model analyze the changes in the stability of the spoil slope under three different numerical simulation conditions.The research shows that under different rainfall intensity,the safety factor of spoiled soil slope decreases with the increase of rain intensity.When the daily average rainfall in the research site area reaches 300 mm,the slope weakens from stable to under-stable.it acts on different rain patterns.The ranking of the safety factor reduction trend of spoil slopes is: equal strength type> rear-forward type> center-forward type>forward type.under different peak accelerations of earthquakes,the safety factor of spoiled slopes decreases sharply with the increase of acceleration.When it is greater than 0.2g,the safety factor of the spoil slope is lower than the critical value 1,and it becomes unstable and forms a landslide;under the coupling effect of rainfall and earthquake,the safety factor of the spoil slope attenuation rate is higher than that under the single factor of rainfall and earthquake.The coefficient attenuation rate,and when the rainfall intensity reaches 100 mm and the earthquake peak acceleration is 0.1g,the safety factor of the spoil slope drops sharply,as low as 0.99,which is less than the critical safety factor,which causes the slope to change its stable state and become unstable.Induce the formation of landslides.Rainfall and earthquake will weaken the stability of the spoil slope respectively.The coupling effect is not just the superposition of two different weakening effects.These two effects will promote eachother and accelerate the weakening of the stability of the spoil slope.