| As the country's emphasis on the development of the western region,Accelerated expansion of construction projects,but the loess landslide hazards is increasingly prominent.Earthquake will cause the slope rock mass damage,looseness,and crack after earthquake,it's easy to generate new landslide under the action of rainfall factors.This has already been confirmed by 5.12 Wenchuan earthquake in 2008,landslide,collapse,debris flow disasters phenomenon have appeared after earthquake.Many regions in the loess plateau are in high intensity seismic region,it have been occurred both Huaxian and Ningxia Haiyuan strong earthquake in the history.So the research of different moisture content loess slope strength and deformation damage deterioration law are essential for analysis post-earthquake secondary,and adopt corresponding measures to prevention disaster and mitigation after seismic load disturbance.In this paper,we discuss the influence of the moisture content of loess slope mainly divided into the following four points: First,research the influence of the water content change to earthquake by rainfall or irrigation before earthquake;Second,secondary disasters caused by rainfall after earthquake.Third,what is the rain effect to the slope.Forth,after earthquake will prone a large number of joints and cracks,discuss the prone influence to the slope when is rain.Research through above four aspects,the main research work is as follows:1.Take Xi'an somewhere undisturbed loess,dividing moisture content to the two groups and that one group has 12%,15%,18%,21% water content of the undisturbed sample.The first group of undisturbed sample will directly to carry on the triaxial test.The second set of sample will vibrating by small earthquake simulation shaking table,then carry on the triaxial test.Compared to two sets of data,make the stress-strain curve and the shear strength,it is concluded that the influence of different moisture content on loess after earthquake,and the influence to the loess strength.2.Use Geo-studio analysis the influence of the earthquake to the different water content of loess slope.The moisture content of loess slope change is usually caused by irrigation and rainfall,so this paper simulation first increase the water content of slope,and then reduce the water content by stable seepage gradually to obtain different moisture content.Simulate the different moisture content slope's earthquake finally,in order to analyze the sensitivity of different moisture content loess slope under the earthquake.3.Use Geo-studio that finite element analysis software simulation analysis the influence of rainfall infiltration in the slope after the earthquake.Analyze both the shear strength and the potential sliding surface of the position change after earthquake,and the influence to the slope safety factor;then analysis the earthquake effect to the slope's joint by Abaqus.Then,analysis the risk of the rain to the slope after earthquake at last.4.It is easy to generate a large number of transfixion crack after the earthquake,fissure permeability coefficient will increase significantly.Through reduction soil strength and increase permeability coefficient to simulate the fracture after the quake,with the analysis of finite element software researcher fissure permeability increases bring the influence to rainfall infiltration. |
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