Study On Geotechnical Constitutive Models And Parameters Commonly Used In Numerical Simulation

With the development of economy, large and complex civil engineering areemerging. These projects have high requirements for foundation stability, andfrequently involve plenty of analysis on stress-strain which is in high stress andcomplex stress paths of geotechnical. At this point, relying on the traditional theory ofsoil mechanics to design and check can not meet the needs of increasingly largeprojects, which we need to study on new methods and models to reflect geotechnicalstress-strain conditions. With the wide application of computer technology and studyon the geotechnical plastic mechanics deeply, the geotechnical constitutive model forthe numerical simulation got a wide development space.The geotechnical constitutive model is not only the core of geotechnical plasticmechanics, but also is the cornerstone of the numerical simulation. In numericalsimulation, selection of the geotechnical constitutive models and reasonable choice ofmodel parameters, determine the validity and accuracy of the numerical simulation. Inthis paper, some geotechnical constitutive models and parameters selection scope ofapplication were focused on. The main work completed is as follows:The basic theories of the geotechnical plastic mechanics were reviewed.Geotechnical constitutive models which are commonly used in the numericalsimulation were introduced, and the advantages and limitations of each model weredescribed.According to the basic principles of geotechnical plastic mechanics, throughmathematical deduction, the modified D-P model and the extended Cambridge modelin numerical simulation range were demonstrated.After the coordinate conversion of the modified D-P model and the extendedCambridge model shape functions, MATLAB software program was used to draw themodified D-P model and the extended Cambridge model in the partial plane of theshape functions.MATLAB software was used to draw the consolidated and drained triaxial shear test data points which are based on slightly dense silt.MATLAB software was used to develop on the procedures of the stress-straincurve about Duncan-Zhang model, modified Cambridge model and hardening model.The theoretical calculation curve of the Duncan-Zhang model, the modifiedCambridge model and the hardening model with the triaxial shear test data pointvisualization were realized. Through the image procedural law which based on thetheory of inverse problem fitting the curve, launched the values of the modelparameters.