Research On Stability Of Jieshibao Landslide And Anti-slide Pile Reinforcement

With the rapid development of China's expressway,its construction area is continuously extending to the northwest of China.The unique loess plateau geomorphic environment is fragile in northwest China,and landslide is the main type of geological hazard in this area.Qingjian to zichang expressway is an important part of qingan line of highway in shaanxi province.The landslide in the tunnel located in the line layout has seriously affected the safety of the proposed highway.Taking zichang jieshibao landslide as an example,the comprehensive collection of regional geological data,combined with field surveying and mapping and exploration,supplemented by in situ test and indoor test methods,the basic situation of landslide,the forming reason and the sliding mechanism were studied.The stability of the landslide is calculated by the transfer coefficient method,and the fracture internal stress,strain,displacement and plastic zone are analyzed by using FLAC3 D to simulate the section.In the end,the influence of the length of anti-slide pile and the distance of pile on the stability of landslide is studied,and the influence rule is obtained,and the design scheme of anti-slide pile governing the landslide is given.The main results of this thesis are as follows:(1)the landslide belongs to the deep and large loess bedrock.The morphological features of this landslide are obvious.On the west side of the sliding body,the shape of the arm-chair is obvious.The front edge of the slide is covered in the high floodplain.(2)using the transfer coefficient method to evaluate the stability of this landslide,in the natural state,the landslide is basically stable and stable;Under the heavy rain or continuous rainfall,the landslide is in unstable to stable state.(3)using FLAC3 D simulation software to simulate the pseudo-three-dimensional numerical simulation of the landslide.The stress of the slope in the vicinity of the slip zone is obviously demarcated.The calculated stability coefficient is similar to the transfer coefficient method.The plastic zone of the slope is concentrated near the slip zone,but it has not formed a penetrating surface.Under the condition of saturation,the landslide stress,shear strain and total displacement are larger than the natural state,and the stability of the landslide is poor.(4)change in FLAC3 D numerical simulation model of anti-slide pile length and pile spacing,focuses on anti-slide pile has proven its governance after the landslide stability influence law: stability coefficient with the increase of pile length and growth,but the pile length is too long,the smaller the influence degree of the pile length on the;The stability coefficient increases with the decrease of pile spacing,and when the pile spacing is smaller,the effect of pile spacing on landslide stability is more obvious.(5)based on the study of failure mechanism and the landslide stability analysis and argument,put forward design scheme of anti-slide pile and carries on the numerical simulation research,It is found that the stability of the landslide after treatment has been improved,and the stability coefficient of the landslide after treatment has been obtained by strength reduction..