Study On The Characteristics Of Landslide Deformation And Stability Of Sunjiaya

Taking the Sunjiaya landslide as the study object,based on the field geological survey,a comprehensive study on the engineering geological conditions of the landslide,slope structure,rock mass structure,slope deformation characteristics etc..The conceptual model of the deformation and failure mechanism of the landslide is established,and the FLAC3 D model is used to conduct the numerical simulation analysis.On the basis of in-depth study on the deformation and failure mechanism,using limit equilibrium method on the stability of the landslide deformation body under different working conditions are analyzed;according to the detailed investigation of the landslide and the analysis of the specific causes,geological conditions and field deformation characteristics,put forward the corresponding prevention and control measures.The main results are as follows:(1)Through field investigation and drilling,find out the Sunjiaya landslide belongs to tectonic erosion of Zhongshan landform,strata occurrence is 200°?16°,landslide slope is 21°,is a gently inclined bedding landslide;find out the basic characteristics of landslide,the formation and composition,which will be divided into landslide three deformation zones: traction deformation area(A),the strong deformation zone(B),gliding nappe zone(C).(2)The installation of landslide displacement monitoring system,the landslide displacement changes in x,y direction of the monitoring,monitoring data from July to September listed the curve;monitoring system ZK02 and ZK03 installed by local residents have not been destroyed,so true and useful data,ZK01 and ZK04 data are normal,the data show that there are signs of landslide sliding,and overlay are sliding,not sliding bedrock.The monitoring time is just after the rainy season,the obtained displacement curve shows that the rainfall has a greater impact on the stability of the landslide.(3)The double ring test was carried out in the field,and the permeability coefficient of the loose silty clay with a small amount of crushed stone and silty clay in the landslide body was about 1.9×10-3cm/s and 1.7×10-3cm/s,respectively.The underlying bedrock is a weakly permeable sandy mudstone,which plays a role of relative water separation,which is beneficial to the enrichment of groundwater in the landslide,which is harmful to the stability of the landslide.(4)According to the effect of rainfall on landslide deformation zone pull groove,the groove forming process is divided into five stages: Crack filling opening—Initial short distance crack initiation—The formation of the trough trough—Further creep deformation stage—Later,the tensile deformation of the slot,leading to the formation of new cracks.(5)using the limit equilibrium method,the calculation of Sunjiaya landslide in the natural,rainstorm and earthquake conditions of stability coefficient,the results show that the natural conditions,the landslide is stable under the condition of rainfall,landslide is unstable,basically stable,seismic condition,landslide is less stable.(6)According to the deformation characteristics of the landslide body and the analysis of the influence factors of the deformation,the numerical simulation of the deformation mechanism of Sunjiaya landslide under natural,rainstorm and earthquake conditions was carried out by using FLAC3 D numerical simulation.The results show that:?Under natural conditions,the landslide stability coefficient is 1.25,the maximum sliding distance is about 4.8cm,the deformation is not obvious,and the stability of the landslide is stable.?In heavy rain conditions,the landslide stability coefficient is 1.09,the maximum displacement is about 13 cm,the local plastic deformation zone through the formation,formation of shear strain increment through belt,local deformation may occur,indicates that the landslide is in a stable state.?Landslide stability did not show the calculated results show that seismic condition,the maximum displacement is about 19 cm,according to the displacement under seismic conditions,formed a displacement zone almost through,the landslide surface in earthquake and soil under earthquake become loose,sliding more likely that landslide is unstable.(7)according to the geographical location,topography,deformation characteristics and the stability of the situation,proposed several measures for landslide prevention is put forward:(1)reducing load and trench backfill;(2)the surface excavation guide drainage;(3)the construction of retaining wall.