Research On The Shear Strength Parameters Inversion Of Rock-soils And The Prediction Of Landslide Disaster

The thesis focuses on the determination parameters of rock-soils and the prediction method of landslide hazard. Basis of the research on shear strength parameters, the thesis applies complex-variable-differentiation method to inverse shear strength parameters. Meanwhile the thesis puts forward the combination method of deformation prediction method, parameter inversion method and strength reduction finite element method to predict landslide hazard along reservoir shoreline. Specifically, the main content and results of the thesis are as following:(1)Basis of the existing study, it analyses the main factors that affect the shear strength parameters of rock mass structure and landslide zone soil, providing reference to the selection of shear strength parameters for engineering practice.(2)With the displacement of measurement points, the paper calculates the strength parameters of rock and soil by the method which is assembly by the rock elastic-plastic finite element method, complex-variable-differentiation method and optimization method. This method has a high calculation accuracy and search efficiency, improving the displacement back analysis of traditional methods. So it has a wide range of applications to engineering practice.(3)Based on the methods of slope stability analysis, it specially analyzes the effectiveness of the strength reduction finite element method. The method can automatically search for the sliding surface slope and the corresponding safety factor. So the method is effective on stability analysis of landslide and the predicting of landslide disaster.(4)With existing data of monitoring points, nonlinear regression analysis, exponential smoothing and gray prediction methods can be used to predict the trend of landslide deformation from a quantitative point of view. Results show that the gray prediction method is closer to the reality in the deformation prediction.(5)Based on deformation prediction of landslide, the thesis establishes the relationship between the displacement and the time, inversing the shear strength parameters of rock and soil. By using the strength reduction finite element method to get the appropriate safety factor, it establishes the relationship between deformation stage and safety factor in order to forecast landslide disaster.