A new uncertainty analysis method based on geostatistical simulation and a case study

The stability of slopes might be influenced by numerous uncertainty factors. In this study, three uncertainty factors are considered in the slope stability analysis, which are locations of weak structural surfaces, structures of soil-rock mixtures, saptial variability of shear strength parameters. One new uncertainty analysis method considing these three uncertainty factors is proposed. And three geostatistical simulation algorithms are used to simulate three uncertainty factors, which are single normal equation simulation, sequential indicator simulation, sequential Gaussian simulation, respectively. When the uncertainty geology model is established, the finite element shear strength reduction method is carried out to calculate the factor of safety. This method is used to the stability analysis of Dahua landslide. The results of the Mont Carlo simulations showed that this method can effectively evaluate the influence of these three uncertainty factors on the slope stability. And the deformation pattern of Dahua landslide has been obtained by this method, which is retrogressive landslide. Then, the influence of the weak structural surfaces’ dip angle to the stability of slopes is discussed. Results show that when there are more vertical weak surfaces the more unstable of the slope.