Stability Analysis Of Gravel-soil Accumulation Slope Under Earthquake

Landslide is a relatively common geological disaster.As one of its main types,landslides of gravel-soil have the characteristics of wide distribution,high frequency of explosion and persistent damage.Slope failure is often induced under certain geological conditions,such as rainfall,earthquakes,and engineering excavation.In recent years,earthquakes have occurred frequently in Sichuan,such as the Wenchuan earthquake,the Lushan earthquake,and the Jiuzhaigou earthquake.The Wenchuan earthquake triggered tens of thousands of landslide disasters,which not only destroyed buildings,but also seriously threatened the safety of human life and their property.Therefore,analyzing the stability of the gravel-soil accumulation slope under earthquake,not only deepen the understanding of the failure mode of the gravel-soil accumulation slope,but also enhance the mechanism of this type slope disaster.It is usefull to help topromote the prevention and control technology,and has certain theoretical significance and practical application value of the project.Based on the field investigation and laboratorytest analysis,this paper uses the limit equilibrium method,the finite element strength reduction method and the discrete element method to compare and analyze the stability of the gravel-soil accumulation slope under earthquake.?1?The stability coefficient of the gravel-soil accumulation slope under different horizontal seismic coefficients is calculated by the transfer coefficient method,and the overall stability of the slope is qualitatively evaluated.?2?Based on the strength reduction method,using the finite element software COMSOL Multiphysics,the variation law of the displacement,plastic zone and safety factor of the gravel-soil accumulation slope is studied under different designed seismic accelerations,and the penetration zone and the potential slip surface position of the slopeare determined according to the plastic zone.?3?Considering the typical unconsolidated medium,discontinuous and other engineering geological characteristics of the gravel-soil accumulation,we sampled some gravel-soil from the Qiaotou slope,located in Xuecheng Town,Li County.The particle size and gradation characteristics of the gravel-soil are studied with indoor screening test.Furthermore,the histogram of the gradation frequency of the gravel-soil was obtained,then the corresponding probability distribution function was fitted.The chi-square test was used to verify the reasonable distribution function.?4?With the discrete element particle flow software PFC^2D,the particle slope model is firstly generated according to the particle size characteristics and gradation probability distribution function of the gravel-soil,then the gravel-soil macrophysical and mechanical parameters are obtained by laboratory test.The mesoscopic parameters of the soil are finally studied.The velocity,displacement and intergranular cracks of the particles at the monitoring point on the slope of the gravel-soil accumulating body under different horizontal dynamic peak ground acceleration are studied,and the potential slip surface is inferred.