Study on landslide mechanism based on dynamic evolution law and numerical simulation method

Abstract

[Objective] The numerical simulation method is widely used in the study of landslide disaster mechanical evolution and plays an important role in the process of landslide control. To study the triggering mechanism of landslide, [Methods]reasonable model assumptions are made, boundary conditions and parameters are set accurately, and a two-dimensional dynamic numerical simulation evaluation method is established. The landslide of Zhangjiazhuang section of Lanzhou-Xin Railway is taken as a typical example. GeoSlope and ABAQUS software are used to analyze the characteristics of landslide main section, slip zone plastic development process, slip region distribution, displacement distribution, and incremental displacement before and after abrupt change, and the landslide mechanism is analyzed by two-dimensional limit equilibrium method. [Results] The result show that the confined water cannot affect the top of the sliding zone, and the reduction of the safety factor caused by the action of confined water on the top sliding surface is smaller than that of the hydrostatic pressure, while the effect of confined water on the bottom of the sliding zone is larger. The reduction of the safety factor caused by the action of confined water on the bottom sliding surface is larger than that of the hydrostatic pressure, and the safety factor is directly reduced by 0.26. [Conclusion] Following the application of confined water pressure, substantial alterations were observed in the Mises stress field adjacent to the sliding zone, with stress increments reaching up to 0.5 MPa.These changes indicated that the action of confined water pressure significantly modified the stress distribution within the landslide mass.Additionally, distinct displacement discontinuities were exhibited by the landslide body under the influence of confined water pressure.Notably, horizontal displacements at the slope crest increased rapidly when the reduction factor reached 1.05.These findings further confirmed the substantial impact of confined water pressure on the stability of the landslide body. Through the comprehensive method and analysis of numerical simulation combined with field investigation and test, the dynamic evolution law of landslide under complex conditions such as groundwater pressure is reasonably simulated, which provides a basis for the stability evaluation of the progressive failure process of slope and the visual dynamic demonstration of landslide.

Keywords

landslide mechanism / ground water / water pressure / dynamic evolution / numerical simulation / safety factor / geological hazard warning / rainfall