Tests On Failure Mode And Dynamic Response Of Two-side Slopes Under Earthquakes

Our country is located between the world's two major seismic zone,therefore,earthquakes occur frequently.For the western mountain area coincides exactly with the seismic belt,the landslides induced by earthquake bring a serious threat to the life and property safety of this area,usually become the most harmful one among the earthquake-induced disastes.Therefore,it has great realistic significance to study the failure law of the seismically induced landslides.This paper relies on the shaking table system in Southwest Jiao Tong University,on the basis of previous studies,makes a preliminary study on the deformation and failure process,failure mode,failure mechanism and dynamic response rules of the slope.Large scale shaking table tests have been designed and accomplished for five groups of slopes under different conditions,mainly discussing the influence on the dynamic stability of slopes by the ground motion parameter and the soil's mechanical properties.Through the analysis of the experimental image data and a large amount of data collected by the sensors,the following conclusions are obtained:(1)The moisture content and compactness have significant effect on the failure mode of the slope,and some influence on the dynamic response rules of the slope.(2)The failure modes of the five groups are superficial collapse slip type,tension shear-collapse slip type,collapse scatter type,creeping slip type and collapse fall type,respectively.The displacement curve of the slope surface can reflect some information of the failure mode to a certain extent,which is helpful to reveal the failure law of the slope.(3)In this experiment,the acceleration amplification coefficient of the surface and the inner of the slope show a significant elevation amplification effect,but the acceleration amplification coefficient along the horizontal direction does not exhibit the characteristics of tend-surface amplification effect.The relationship between the acceleration amplification effect and the amplitude of the input wave is affected by the moisture content of the slope.With the increase of the input wave frequency(approaching the natural frequency of the slope),the acceleration amplification coefficient of each point in the slope increases.The dynamic response of slope to low frequency sine wave is not obvious.(4)The experimental results commendably verify the first motion tensile and shear acceleration rending effect,repeatedly tensile and shear rending effect and double-side common shear rending effect of two-side slopes under ground shaking,which is significant to further reveal the failure mechanism of two-side slopes under seismic action.