Shear Strength Parameters Inversion Analysis And It’s Applicationon Slope And Landslide Engineering

Stability analysis is an important study content of slope and landslide engineering, as an important parameters for stability analysis and reinforcement design of slope and landslide, shear strength parameters is reasonable or not, directly influence and determine the veracity and reliability of slope and landslide stability analysis and reinforcement design.At home and abroad, the means of test method and experience method used to determine the shear strength parameters of slope and landslide still have many deficiencies, so inversion analysis method is increasingly becoming a reliable means to determine the shear strength parameters of slope and landslide, but the limit equilibrium method, the limit analysis theory and the displacement back analysis method are not very perfect. Therefore, based on the systematic analysis of the existing methods of shear strength parameters of slope and landslide, first of all, aimed at simple slope with monitoring displacement data, the inversion method of shear strength parameters of slope is proposed by combining with the strength reduction method and displacement optimization back analysis method; Secondly, aimed at the slope and landslide without monitoring displacement data, a method is proposed to inverse the shear strength parameters by contacting the intrinsic law between the position of the sliding surface and the shear strength parameters; finally, aimed at the bedding rock slope with weak interlayer, based on a landslide engineering of Lan Yong first grade highway, according to its instability condition and deformation characteristics, shear strength parameters of structural plane is inverted based on the model of rigid body slip, at the same time, the inversion results are applied to the reinforcement design and stability analysis of the similar slope along the Lan Yong first grade highway, good results are obtained, the main results and conclusions are as follows:1. Aimed at simple slope with monitoring displacement data, under the condition of selecting the initial value of the reasonable shear strength parameters, fitting the relationship between the manual reduction coefficient and displacement, combined with displacement back analysis method, the inversion method of shear strength parameters of slope is proposed based on strength reduction method, this method can be used to improve the effect of shear strength parameters on displacement, and avoid the complicated program and the tedious mathematical calculation;2. Aimed at the slope and landslide without monitoring displacement data, based on the accurate determination and connection of the position of the sliding surface, contacted internal rules between the position of the sliding surface and the shear strength parameters, and combined with Bishop method, the inversion method of shear strength parameters of slope or landslide is proposed based on the position of the sliding surface,it is a good way to overcome the non-uniqueness of the shear strength parameters of the single slip surface;3. With the bedding landslide engineering at the k23+520 of Lan Yong first grade highway as a example, aimed at the bedding landslide with slip-tensile failure modes, under the condition of determining the range of strength parameter c、 j according to the properties of the structure surface, a method is proposed based on the model of rigid body slip and the correction measures, this method can obtain the structural plane shear strength parameters which meet the requirement of engineering application through the instability condition and the deformation feature to correct step by step;4. The shear strength parameters obtained from inversion are used in the design of reinforcement of slope, analyzed the deformation tendency, the position of the sliding surface and the force of the support structure through the finite element software found: the supporting structure has great force of the bedding rock slope with weak interlayer on the weak structure, in order to ensure the overall stability of the slope, the corresponding reinforcement measures are taken to meet the requirements of the stability of the structure plane;5. Slope and landslide with monitoring displacement or no monitoring displacement data, the key to the inversion of shear strength parameters is the determination of dimensionless parameters, with Lizheng geotechnical software, according to Bishop slice method, the final value is determined by the error analysis of the stability coefficient and combined with the position of the sliding surface.