Stability Analysis And Failure Process Simulation Of Loess Lanslide

In recent years,geological disasters of loess landslide occur frequently,which has attracted great attention of many experts in related fields.This dissertation takes the loess ancient landslide in a mining area of Liulin County,Shanxi Province as the research object.Through field investigation and a series of tests,the geological conditions of the site and the relevant parameters of rock and soil mass were obtained.This dissertation focuses on the stability analysis of the loss landslide,and then studying the disaster-causing scope of the disaster.The targeted reinforcement management scheme was put forward and simulated.The main research contents of this dissertation are as follows:(1)By referring to relevant literatures,the research status of loess landslide stability analysis and post-disaster disaster-causing scope simulation at home and abroad were deeply grasped,and the problems existing in the current researches were deeply analyzed.(2)Based on the field survey,the causes and stability of the ancient landslide in Liulin County,Shanxi Province are analyzed from the geological perspective.Based on the analysis of its natural geographical factors,regional geological situation and engineering geological conditions,the formation mechanism of landslide is studied.It is found that the three ancient landslides are all caused by their geographical location,meteorology,hydrology and geotechnical structure,and the formation of ancient landslides is inevitable.(3)The typical section of GH1 ancient landslide was selected,and numerical modeling was carried out by using the finite difference code FLAC and the discrete element code PFC.Then the landslide stability was retrieved by FLAC to obtain the soil parameters in the ancient slide zone.Calibration of the soil physical and mechanical properties is made by PFC biaxial test.Then the stability of different sections of GH1 ancient landslide under natural condition is analyzed.It is found that the safety factors of the three sections are all greater than 1,and the slope is not damaged,but there is the possibility of instability failure.Through analysis and comparison,the most dangerous section 3-3 of the ancient landslide is found.(4)For the most dangerous section of GH1,the PFC code was adopted to import the unidirectional and bidirectional seismic loads,as well as the seismic loads of different magnitudesizes,respectively,to analyze the instability failure forms and post-disaster disaster range of the most dangerous section of the GH1 loess slope under the unidirectional,bidirectional seismic loads and different magnitude-sizes.The displacement and velocity responses are tracked by setting measurement circles and feature points in the slope model area.The results show that the vertical load has a certain influence on the stability of GH1 loess slope,and the disaster-causing scope of GH1 loess slope increases after failure under bidirectional seismic load;Seismic loads with different magnitudes have a certain influence on the stability of the GH1 loess slope,and with the increase of the magnitude of the magnitude of the earthquake,the disaster-causing scope of the GH1 loess slope increases after failure.(5)For the most dangerous section of GH1 loess slope,according to the “Specification of design and construction for landslide stabilization”,the reasonable prevention and control measures are put forward,and the rationality and reliability of engineering slope cutting and antislide pile reinforcement scheme are simulated and calculated to verify the rationality and reliability.The simulation results show that the overall stability of GH1 loess slope is improved under the effect of engineering slope cutting and anti-slide pile support,and the engineering slope cutting is beneficial to improve slope stability,while anti-slide pile reinforcement effect is better.