Experimental Study On Strength Of Slip Zone Soil Considering Residual Shear Stress And Analysis Of Landslide Stability

China's loess area is extensive,and the main distribution area is located in Yan'an.There are a large number of loess landslides in Yan'an area.Due to the rapid development of regional economy in recent years,human engineering activities have seriously affected the stability of landslides.Landslides and other geological disasters occur frequently in Yan'an area,which seriously affects the safety of life and property of the local people.Taking Dingjiagou Loess Landslide as an example,this paper carries out the corresponding experimental,computational and simulation studies to provide reference for the treatment of loess landslide in this area.In this paper,the strength characteristics of loess landslide sliding zone soil are studied by direct shear test,especially the relationship between regeneration strength of sliding zone soil and residual shear stress of sliding surface.Finally,the stability of loess landslide is simulated by FLAC3 D software based on the strength test results of sliding zone soil.The main work and conclusions are as follows:(1)According to the strength characteristics of sliding zone soil and the stability analysis of landslide in this paper,the research status of residual strength,regeneration strength characteristics of sliding zone soil and landslide stability based on the strength characteristics of sliding zone soil at home and abroad are introduced in detail,and the significance of landslide stability analysis method based on residual shear stress level is expounded according to the current research shape.(2)The engineering characteristics of Dingjiagou loess landslide are introduced in detail,and the deformation state of the landslide is analyzed in detail.The stability of Dingjiagou loess landslide is analyzed and evaluated by transfer coefficient method.The results show that the landslide poses a serious threat to the safety of residents lives and property.It is suggested that support and reinforcement of the new landslide should be carried out.(3)The shear strength,residual strength and regeneration strength of sliding zone soil are obtained by direct shear test.The regeneration strength of sliding zone soil based on residual shear stress level is studied emphatically.The regeneration strength of sliding zone soil is stable first and then decreases with the increase of residual shear stress,and the values of cohesion c and internal friction angle are obtained.(4)The FLAC3 D numerical simulation of landslide stability is carried out by using the distribution of residual shear stress on the sliding surface and giving strength parameters in segments.The result of stability evaluation of loess landslide is more in line with the actual situation,which provides a reference for stability analysis and evaluation of this type of loess landslide and landslide treatment.