Application of numerical modelling to the comprehensive analysis of slope stability
Document typeConference report
Rights accessOpen Access
Paper deals with the comprehensive methodology for the numerical simulation of potentially unstable slopes combining engineering geological, hydrological, hydrogeological and geotechnical computational model for the assessment of slope stability. Engineering geological model based on available survey data characterizes the rock environment using individual quasi-homogenous units. Model is defined on the basis of documented lithostratigraphic units in exploration probes and field relief documented by advanced methods, including satellite radar interferometry and laser surface scanning. On the basis of engineering geological model, the hydrological model using MIKE SHE software (Finite Difference Method) was performed. Hydrological model includes simulation of surface runoff, evapotranspiration and flow in unsaturated near-surface zone. The model was calibrated on the basis of available field data. Outputs from this model were used as input initial conditions of the following hydrogeological model. Software FEFLOW based on the Finite Element Method was subsequently used to the creation of hydrogeological model focused on the water flow and distribution of pore pressures of groundwater in individual quasi-homogeneous units in saturated zone. The infiltration condition determined by the hydrological model is considered and a flow model with variable saturation is applied. Finally, the geotechnical stability model of slope following the engineering geological, hydrological and hydrogeological models was performed. The occurrence of plastic and failure zones (assuming elastic-perfectly plastic Mohr-Coulomb constitutive model) inside the slope was simulated by using software MIDAS GTS NX based on the Finite Element Method. Stability factor SSRF (Shear Strength Reduction Factor) is evaluated based on the Shear Strength Reduction Method) as the ratio of actual shear strength and minimum shear strength required to maintain stability. Paper deals also with the comparison of stability factor of natural slope obtained from 3D and 2D numerical model. Generally, in the case of natural slope the condition of plane strain is not fulfil, 2D model is not realistic and 3D model is needed, especially in case of concave morphology of slope.