Numerical Simulation Of Landslide Stability Based On FLAC^3D In Guanzhong Loess Plateau Region

Loess slope failure is a common geological disaster in a loess distributing area covering roughly 640,000 square kilometers. With its complex cause, complex structure and frequent occurrence, it has posed a threat to human life and regional economic development, as well as the safety operation of highway fundamental transportation infrastructure. Over the past few years, the majority of scholars devoted to researching have achieved a breakthrough in the aspects of mechanisms of occurrence, influence factors and engineering geological properties of landslide. But due to the wide variety of mechanisms of slope failure occurrence and numerous influencing factors, highway transportation is still facing a great threat. Owing to the existence of weak intercalated layer inside the slope body and special sliding mechanism, the striking features of slope failure along the S107 provincial road is worthwhile for us to have an intensive study.The paper relies on Weinan-Yangguo section of S107 route, the thesis focuses on the analysis of structure characteristics of landslide and engineering geological properties of slip-zone soil in the plateau form area on the premise of sufficient collection of geology and reconnaissance data and related laboratory report. It is found that the engineering properties of Hipparion red clay(N2) in the slip zone are complicated, and its engineering properties enable the slope to have a complete development, i.e. to induce the occurrence of landslide, especially on the rainfall condition. Hipparion red clay, in which the weak slip zone is formed, is located in the paleosol layer of stratum structure, and its specific position can’t be determined through theoretical calculation; information technology therefore is of assistance in searching.Taking 1# and 2# landslides as the prime engineering example. The results show that the landslide is in the state of instability from the landslide safety factor obtained by residual sliding thrust method, meanwhile they are also verified with the results of reconnaissance in order to find the incentive of their landslide. Then the regulation scheme of landslide is established according to the calculation results of thrust.The results are verified further under normal and rainfall two kinds of conditions by strength reduction method in FLAC3 D numerical simulation software. The results obtained are consistency with the limit equilibrium method and field reconnaissance. The slip-zone position can be searched by numerical simulation, meanwhile, it also can be roughly obtained by plasticity chart and shear stress increment chart of the results. Displacement and stress chart are able to give an analysis of the relationship between the stress and strain, as well as the striking features of slope failure, etc.stabilizing pile is applied into numerical simulation in terms of slip-zone position and the principle of treatment. It is found that landslide is toward to the stabilization and the safety factors are guaranteed from simulated displacement chart and reduction coefficient relation curve. There is a larger reduction in the strain range of shear stress chart. It is indicated that sliding zone has been under control from the pile’s internal force and bending moment diagram, and treatment measures are reliable.Construction design can be guided based on the research of this paper, and protective measures along the route have been completed. After monitoring and the field investigation, treatment measures are reliable. They play a positive effect on geological hazards management and reduce the loss of hazards. Research results can serve as a reference for the similar project in the future.