Stability Analysis Of Zhaojialing Landslide And Simulation Study On Its Reinforcement Effect

The research object of this paper is Zhaojialing landslide,which is located in Zhangfang Town,Liuyang City,Hunan Province.Through the geological survey,the engineering geological conditions,deformation and failure characteristics of the landslide,and the deformation and failure mechanism of the landslide were studied comprehensively.The limit equilibrium method was used to analyze and evaluate the stability of the landslide under two working conditions.In order to study the stability of the landslide more deeply,the three-dimensional conceptual model of the landslide was established by ANSYS and FLAC3 D software,and then numerical simulation and analysis were carried out.According to the deformation trend and characteristics,the corresponding prevention and control measures were proposed,and the optimization comparison was carried out.The following were the research results of this paper:(1)Through the on-site investigation,the distribution characteristics of the landslide and the position of the sliding zone were ascertained by means of drilling and geophysical exploration.The sliding body of the whole landslide is the residual soil of granite.The sliding zone is roughly the contact surface of the sliding body and the fully weathered granite.The influencing factors and deformation and failure mechanism of the landslide were identified.The landslide belongs to the resurrection of the old landslide and was most affected by groundwater.The old sliding body produces creep deformation,which promotes the large-scale slope instability in the front.It is a typical sliding landslide,which causes the natural slope of the trailing edge of the landslide body to deform and slip,forming a traction landslide.(2)Using the limit equilibrium method,the stability coefficients of the landslide under natural and heavy rain conditions were calculated.The calculation shows that in the natural state,the safety factor is 1.11~1.17,and the state of the landslide tends to be basically stable;In the heavy rain state,the safety factor is 0.96 to 0.99,and the state of the landslide tends to be unstable.(3)Using numerical analysis method,the landslide was numerically simulated by FLAC3 D,and the deformation and failure characteristics of the landslide were studied from the plastic deformation zone,stress field and strain field under natural and heavy rain conditions.The comparative analysis under the state,the stability of the slope in the rainstorm state is worse.The calculation results show that in the natural state,the safety factor is 1.12~1.2,the landslide state tends to be basically stable;in the heavy rain state,the safety factor is 0.98~1.02,and the landslide tends to be unstable.(4)A design scheme for prevention and control of landslides was proposed.The anti-slide piles and prestressed anchors were used to reinforce the areas I and II of the landslide respectively.The numerical analysis showed that the anti-sliding requirements were met.On the basis of this,the support effect of the anti-slide pile arrangement spacing,anchoring depth and section size under different conditions were studied by numerical simulation.The simulation results of the horizontal displacement,bending moment and shear force of the anti-slide pile were respectively made.Comparative analysis,and proposed an opimization scheme for anti-slide piles,using anti-slide piles with a pile length of 26 m and a spacing of 4.5m and 2×3m.