Stability Of Slope Under Coupled Action Of Earthquake And Rainfall Analysis

Rainfall and earthquake are the main influencing factors of slope failure.The two mechanisms of slope failure are quite different.The southwest region not only has frequent earthquakes but also has abundant rainfall.After the Wenchuan earthquake in 2008,the rainfall often occurred in the earthquake area and the aftershocks continued,resulting in a large number of secondary disasters.Therefore,it is of great significance to study the slope stability under the coupling effect of rainfall.This paper from the rainfall,earthquake and rainfall_seismic coupling of the three condition,to explore the mechanism of coupling effect on the slope.The main contents are as follows:(1)Based on the fish platform of FLAC3 D,the slope rainfall program has been compiled,and the influence of rainfall intensity and rainfall duration on the slope stability has been studied.Under different rainfall intensities,the pore water pressure in the slope presents different rising patterns.Under the continuous action of rainfall,the extent of transient saturation area is increasing.When rainfall time is long enough,the main change of slope is the decrease of matrix suction in the slope.In the early period of rainfall,the stability coefficient of slope decreased rapidly.With the increase of pore water pressure in the slope,the slope stability coefficient gradually slowed down,and the influence of the change of rainfall intensity on the slope stability was becoming weaker and weaker.(2)The seismic wave is applied to the slope containing groundwater.The failure mode of the earthquake action on the slope is studied by controlling the maximum peak acceleration of the seismic wave.After the earthquake,the displacement of the slope showed varying degrees,but the change values were very small.At the foot of the earthquake,the plastic damage occurred at the foot of the slope,and the damage range increased to the surrounding area with the increase of the peak acceleration,and the damage in the plastic zone stopped after the earthquake.For the unsaturated zone in the slope,the pore water pressure in the slope increases with the earthquake action,which leads to the decrease of the matrix suction of the slope,but it has little effect on the stability of the slope.(3)After the rain on slope applying seismic wave to slope failure mechanism of rainfall_earthquake under the coupling effect.The seismic action made the pore water in the transient saturated area of the slope be extruded,which increased the stability of the surface rock and soil to a certain extent.As the rainfall continues,the effect of seismic force on the stability of the slope becomes weaker and weaker by changing the matrix suction in the unsaturated zone and affecting the shear strength of the slope.When the rainfall time is long enough,the influence of the relative earthquake on the slope stability is greater.The occurrence of the slope after rain enlarging the influence of rainfall on the slope,and then accelerating the slope instability.The failure of slope and top slope under coupling action is mainly shear and tensile failure,and the destruction in the slope is mainly shear failure.(4)Wang Yan in the Luzhou Naxi landslide as an example,the slope stability of rainfall and rainfall_seismic coupling condition analysis.Under the action of rainfall,the pore water infiltrates into the middle of the slope along the geotechnical interface,and a large range of active shear plastic zone appears at the interface,but it is not formed along the geotechnical interface,and the slope is in a stable state after the rain.Seismic waves are applied to the slope after rain,and the slip state of the potential slide is excited.The sliding body does not continue to slide after the end of the earthquake,there is an active shear zone in the front of the slide body,and the slide body has two risks.