Research On Formation Mechanism Of Gently Inclined Landslide And Its Prevention And Control Technology

The formation mechanism and conditions of the gently inclined landslide is very special,and the study on it is still inadequate and with much controversy.In view of this,after the summary on the previous reinforcement measures on slopes and earth retaining structures,and taking the Mingxi Gently Inclined Landslide project as an example,and also based on the current research results on the gently inclined landslide,the features,induction factors,deformation mechanism,reinforcement measures and the corresponding reinforcement effects of the gently inclined landslide were studied in detail in this thesis.It aims to build the general geological model and failure analysis model of the landslide so as to provide some guidance for the future treatment of such gently inclined landslide.The main work and conclusions are as follows:(1)Based on the Mingxi Gently Inclined Landslide project,the atmosphere and water resources,geological condition,topography and geomorphology,human engineering activities etc.were studied,the deformation and stability of the slope were analyzed so as to find out the deformation and failure mechanism of Mingxi Gently Inclined Landslide,and the factors of safety of the slope under different underground water conditions were calculated.It is suggested that the drainage should be the predominant measures on the treatment of gently inclined landslide while the retaining structure should be the supplementary.(2)Based on finite element method,the influence of the rainfall and underground water is taken into consideration by the generation of weak slip surface and the application of hydrostatic pressure on the trailing edge and the uplift pressure on the bottom of the landside body,then numerical analysis is done on Mingxi Gently Inclined Landslide based on different rainfall and underground water conditions so as to simulate the whole process of landslide and study the effect of rainfall and underground water on the failure mechanism.(3)Four treatment conditions,i.e.,Case 1(drainage only),Case 2(anti-slide pile),Case 3(anchor anti-slide pile)and Case 4(anchor anti-slide pile with anchor on the trailing edge),are studied numerically to analyze the static and seismic response of Inclined Landslide.It turns out that the factor of safety of the slope with drainage treatment is increased from 0.86,which is the worst condition,to 0.98,while the factor of safety of Case 2?Case 4 with different anti-slide pile treatment after drainage treatment is 1.16,1.23 and 1.35,respectively,what is more,the deformation of the slope decreases gradually,which validates the effectiveness of drainage,lowering ground water and anti-slide pile reinforcement.(4)As the earthquake loading goes higher,the bending moment of anti-slide pile becomes larger,and the bending moment of anti-slide piles in different cases exhibits similar trend.That is:as the burial depth increases,the bending moment goes larger and reaches the peak at about 2?3m under the weak slip surface,and then it gradually decreases with depth.The maximum bending moment locates near the slip surface,which helps to inhibit the sliding trend of landslide mass.And it also indicates the weak point of the pile body,it is necessary to reinforce the pile body at about 2?3m under the weak slip surface during the seismic design of slope.