Research On Constitutive Model Of Rock And Soil Mechanical Parameters With Different Values

Rock and soil mechanical parameters and constitutive models are the basis for slope stability analysis and protection engineering design calculations.The values of mechanical parameters are usually determined by experimental data combined with a regression analysis method,and there is no comprehensive comparison of the advantages and disadvantages of various methods.Therefore,it is necessary to study the value of mechanical parameters under different methods.The constitutive model also involves the problem of the value of the mechanical parameters.How does the difference of the parameters affect the accuracy of the constitutive model fitting,and then has the accurate calculation of slope stability analysis and the accurate layout of anti-slide facilities What influence is worth exploring.This article focuses on the influence of different parameter values on the fitting accuracy of the new constitutive model,mainly including the following points:(1)With the theme of the method and constitutive model of the mechanical parameters of rock and soil as the subject,the mathematical statistical characteristics of the mechanical parameters of the soil and its value are summarized,and the current main constitutive models are described,Analyze its advantages and disadvantages,and provide a reference for the research in this article.(2)Introduce the basic principles and solution steps of least square method,point group center method and random-fuzzy method,and summarize the similarities and differences of the three methods.Among them,the least square method only considers the randomness of the parameters,and does not consider its fuzzy The point group center method is subjectively influenced by people.Both of these methods are limited to outliers;the random-fuzzy method uses parameters as random-fuzzy variables,and the optimal solution can be obtained by iteration,but it is limited The membership function.(3)The mechanical behavior characteristic curves of rock and soil are extended from two types to three types,and a new constitutive model that can describe the two types of curves ? and ? is introduced,including shear stress-strain and principal stress-strain.The two forms have similar model characteristics.The model can not only describe a variety of mechanical behavior characteristics,but also can explain the problem of stress and strain discontinuities in the area after rock and soil failure.(4)Using Matlab software as a platform,the optimization of three rock mass mechanical parameters and the new constitutive model were programmed,and the new constitutive model was designed with a GUI visual interface to realize parameter input And the visualization of the output of the fitting results greatly improves the efficiency of the calculation.(5)Taking a certain clay soil shear test and a concrete triaxial test as examples,calculate the cohesion and internal friction angle under the three value methods,and apply it to the stress-strain relationship in the new constitutive model Fit and compare the new constitutive model with the Duncan-Zhang model;research shows that all three methods can perform good regression analysis on the parameters,and the new constitutive model also has a good fit for the stress-strain relationship.It is better than the Duncan-Zhang model,but the deviation of the accuracy of the parameter value causes the accuracy of the new constitutive model to fit the experimental data.Therefore,in the analysis of the parameter value,multiple methods should be considered comprehensively to select the optimal parameter value and applied to theoretical research and engineering design.