Von-Wolffersdorff Hypoplastic Model And Its Application To Stress And Deformation Analysis Of Concrete Face Rockfill Dam

Hypoplasticity theory in simulation of sand material stress-strain characteristics is verified and widely used,and will be able to describe material properties and void ratio of hypoplastic model is introduced into the rockfill material which is different from the traditional constitutive model.At present,the engineering application is less.According to Fujian province Xianyou pumped storage power station dam reservoir project example,through the improvement of the von-Wolffersdorff proposed hypoplastic constitutive model makes the stress and strain of rockfill is more suitable for the analysis,and three conventional triaxial test and the engineering stress-strain curve fitting comparison to model validation and comparison of calculation results finally,the finite element calculation results with the work of Duncan E-B model,Shen Zhujiang model,the calculation results with the overall Shen Zhujiang model closer to the application of improved von-Wolffersdorff model test in the analysis of stress and strain of rockfill dam is feasible.(1)The basic concepts related to the theory of plasticity are briefly described,and the theory of von-Wolffersdorff hypoplasticity model,the derivation process and the method of determining the parameters in the equation are emphatically explained.(2)The conventional three axis test data of the existing project is brought into the von-Wolffersdorff hypoplasticity model,and the stress-strain curve is compared with the test curve,and the shortcomings of the model are improved.The main improvement method is to change the alpha and beta of the model parameters with the confining pressure and increase the volume strain,so that the model is more suitable for simulating the stress-strain of rockfill materials.(3)The application of improved von-Wolffersdorff model equations to nonlinear finite element solution of concrete face rockfill dam of the project,set up between the equation and the modulus matrix[D],simulation of loading process of rockfill dam construction period and storage period using the midpoint incremental method to develop von-Wolffersdorff model finite element program improvement.(4)The improved von-Wolffersdorff model with CAD finite element program and GiD program interface is formed the engineering stress and strain calculation results presented in graphical form,and engineering application on Duncan E-B model,the high degree of recognition and Shen's double yield surface model in dam settlement,the panel deflection,the panel along the slope and dam axis to normal stress and peripheral joi'nt opening etc.The results of comparative analysis,the rules and results of both models and similar,which verifies the feasibility of the improved von-Wolffersdorff model for stress and strain of the reactor should be stone dam.