Abstract:

Landslide disaster which should be considered as a nonlinear dynamic system has strong spatial variation and randomness. Using the transmission coefficient method at different safety factors, the slip soil of Dagouwan Landslide is analyzed inversely; and the relationship between shear strength parameters on conditions of critical state and limited water level is obtained. Analyzing the shear strength parameters gotten by shear tests and combining engineering geology analogy, the distribution of shear strength parameters is obtained by statistic method; then the stochastic shear strength parameter is generated. Supposing Mohr-Coulomb criterion obeys linear distribution in the range of slide mass gravity stress, with the ? -? distribution curve cluster gotten from shear test, taking the range of slide mass gravity stress into account, the c-? envelope polygon is obtained. With the envelope polygon, the effective stochastic shear parameters are selected. After Monte Carlo simulation, the failure ratio of the landslides at different safety factors are calculated based on the distribution relationship between effective stochastic shear parameters and the limit equilibrium c-? curves gotten by the inverse analysis. The prediction shows the stability of Dagouwan landslide is very weak at limit water level. Combining the twice field survey on Dagouwan landslide in the process of water impoundment, the results are identical.

Key words: Dagouwan landslide, inverse analysis, transmission coefficient method, correlation between parameters, failure probability