Slope Mechanical Parameter Inversion And Stability Research Based On Interval Displacement Inverse Analysis Method

With the continuous improvement of computer technology and intelligence level,researchers are increasingly inclined to use numerical simulation as an analysis method for slope engineering scheme design,construction scheme selection,and evaluation of deformation and stability.However,the reliability of numerical simulation depends to a large extent on the accuracy of rock and soil material parameters.However,due to the influence of instruments,natural or human factors,the selection of rock and soil material parameters is disturbed by uncertain factors.It is not the parameter value in the actual project.At present,the quantitative treatment of uncertain factors is still a research topic that has attracted much attention in the engineering field.Therefore,this paper uses the measured displacement data to invert the physical and mechanical parameters of the slope,and adopts interval analysis to represent the uncertainty and It is introduced into the traditional displacement back analysis,and the system of interval back analysis-stability positive analysis is realized by writing the program of interval displacement back analysis.The main research results of this paper are as follows:(1)The method of inversion of slope mechanical parameters based on interval displacement inverse analysis and positive stability analysis is proposed.On the basis of interval analysis theory and displacement inverse analysis theory,by introducing interval mathematics as a mathematical tool for uncertainty analysis,improving the objective function by using the sequential interval number ranking method,combining with constraint optimization algorithm to search for the optimal radius of the parameter values to be inverted,the interval displacement inverse analysis program is prepared based on the joint calculation toolbox of MATLAB platform,and verified by one side slope The comparison between the inverse analysis interval parameter values and the inspection values shows that the program can reasonably control the errors caused by uncertainty factors within an interval.(2)The inversion of the physical and mechanical parameters of the unloaded slopes was carried out to clarify the influence of excavation unloading on the stability of the slopes.The interval displacement inverse analysis program is used to perform interval parameter inversion for the parameters that have passed the sensitivity analysis with error percentages ranging from 0.15% to 2.48%.The stability state of the landslide before and after excavation and unloading was analysed by numerical simulation.The inverse interval parameter values are used in the actual project and also as a reference for the design and protection of the slope.(3)The inversion parameters of the multi-layered reservoir bank slope were obtained to reveal the influence of water level changes on the stability of the reservoir bank slope.The key sensitivity parameters of each of the four strata of the reservoir bank slope are inverted,and the parameters are selected as the input values of the model parameters by setting the step cycle,and the interval stability coefficients of the slope at different water levels are obtained by using the orthogonal design for multiple numerical simulations of the reservoir bank slope.The interval parameters and interval stability coefficients of the inversion of the landslide at 175 mm water level are analysed to illustrate the transfer of errors in the inverse analysis of interval displacements and to reveal the phenomenon that the existence of errors in slope engineering affects the final positive analysis results.