Reliability Analysis Of Landslide Stability And Its Application Based On Monte-Carlo Random Number Method

Landslide is a natural geological phenomenon which is severely harmful to the mankind. Evaluation of landslide stability has also been the focus and hotspot in the research of geotechnical engineering. Nowadays, the main method for landslide stability analysis is the limit equilibrium method, and the safety factor is also chosen as the primary evaluation index. In this method, the mean values of physical and mechanical parameters for rock and soil are calculated to give the certainty evaluation of landslide stability. For the analysis, the uncertainties of geotechnical parameters are not fully considered, and the discreteness and variability of parameters is ignored. Correspondingly, the calculation results are difficult to accurately and comprehensively reflect the overall safety state of landslide. However, based on the probability of random distribution, the reliability analysis method can adequately be considered the variability of geotechnical parameters. It fully considers the uncertainty factors from the source of landslide evaluation; so, the evaluation results are more reasonable and comprehensive. Therefore, the reliability analysis engineering design and safety assessment will produce obvious more value in application and important significance in practice. Moreover, reliability analysis method has gradually become the main method for landslide stability.In our study, we firstly evaluated the stability analysis method of landslide based on the limit equilibrium method, and analyzed the advantages and applicability of reliability theory. Then, we calculated the instability probability of landslide and reliability index based on the reliability method, and the advantages of Monte-Carlo stochastic simulation method was also analyzed. Moreover, we established the corresponding Monte-Carlo random methods for Sweden slice method, Bishop method, Janbu method and residual thrust method in stability calculation of landslide, respectively. Finally, we solved the landslide failure probability and reliability index, and comprehensive evaluated the stability state of Tongzi River ancient landslide.We analyzed the influence of the random simulation times, variability and the distribution of geotechnical parameters on the reliability sensitivity of landslide stability. Our results are shown that random simulation times had a great influence on the reliability index, and the internal friction angle had a more significant effect than cohesive force, yet the distribution of geotechnical parameters had a low effect. Finally, we evaluated the steady state of Tongzi River ancient landslide in view of the reliability index. Our research should be helpful to the prevention and treatment of this landslide.