Study On The Forming Mechanism And Stability Of Fengmaoding Slumping-rebounding-slumping Landslide In Gujiao City

With the infrastructure build massively in our country,such as mining,water conservancy,transportation and so on,the more landslides take place,the more their forming mechanism are , and Fengmaoding slumping-rebounding-slumping landslide in Gujiao city is typical of them.At first,its body slides down.Secondly,sliding displacement decreases gradually.At present , its body slides up and sliding displacement increases by degrees.Therefore,it is very essential and necessary to study the forming mechanism and stability of slumping-rebounding-slumping landslide.In this paper,introduced an overview of presently available literatures about landslide and its stability at home and abroad,the study begins aim at Fengmaoding slumping-rebounding-slumping landslide in Gujiao city.Proceeded from regional geo-environment and morphological features of landslide,through local investigation,field work and collection of pertinent date,and combining with laboratory-test result , the results show that Fengmaoding slumping-rebounding-slumping landslide is effected by topography,formation lithology,fault tectonic,slope excavation,underground mining and so on. Through analysis of deformation actuality in landslide area,the witnesses that mountaintop sink,mountainside shove outward and the foot of a hill arch. After analysing synthetically natural factor and anthropogenic factor of effecting Fengmaoding slumping-rebounding-slumping landslide , three geological models witch are no fault and no underground mining model,fault and no underground mining model,fault and underground mining model are build.they are modeled by Rock Failure Process Analysis-Strength Reduction Method(RFPA-SRM)witch accomplishs the finite element method as a tool of stress analysis,Mohr-Coulomb criterion and the maximum tensile stress or tensile strain criterion as strength criterion,satisfys the static equilibrium and strain compatibility,considers no-homogeneity and relation between stress and strain of materials.Through analysis and comparison of simulation results,the follows conclusions are obtained:1,While Fengmaoding is no fault and no underground mining,first of all,rock landslide happens in the vertical slope of the upper part of the railway.After the fissures of slip plane extend upward to ground,its trailing edge rock or soil body forms landslide again.2,While Fengmaoding is fault and no underground mining,in the first place,landslide takes place between the railway and road.Thanks to the fissures of slip plane extend upward,rock or soil body of vertical slope in the railway slumps again.3,While Fengmaoding is fault and underground mining,above all,the roof and floor of goaf access completely.Afterwards,landslide only occurs between the railway and road.With it,subsidences arise in the ground.4,The underground mining activity which aggravates the formation of landslide is the main factor of Fengmaoding slumping-rebounding-slumping landslide.