The Test Research And Numerical Simulation In Scale Effect Of Soil

The complex interactions between soil particles determines the mechanical properties of soil have obvious scale effect. In this paper, based on the process of soil deformation in the " size effect" phenomenon, from microscopic view considering the soil particle interaction mechanism, use different particle size and gradation to give a soil original experimental which can determine the deformation scale effect and gives the soil scale effect law and mechanism of the experimental results. Basing on soil micro-particle interactions, we also proposed a original " matrix - strengthen particle" crack theory model which can effectively reflect the scale effect of stress strain relationship and give intrinsic scale calculation expressions of this model. According to the deformation of clay" size effect" characteristics, originally build the mechanism which contains " strain gradient particle size continuum", which can fully contact the macro - micro scale effect of. Based on the micro level of soil particle movement form, according to the modern theory of tribology, establish an original double yield surface failure mechanism which particles in micro rolling and sliding, and the establishment of a couple stress space yielding flow rule and hardening mechanism. Based on the above particle scale continuum mechanics, we make a new finite element analysis program, and use it to calculate a soil column with axial symmetrical loads and natural slope in the symmetry axis loads to study the scale effect simulation. The simulation results and actual engineering deformation localization is nearly consistent. The program can simulate the localization occurs, development, failure process. The model and program to the classic elastoplastic mechanics in calculation of plastic zone localization will centralized characterization to a zero scale problem, namely the calculation process with element sensitivity problem. But our program overcome problem of the classic plastic theory model which is based on continuum mechanics frame without geometric size point up, which can only simulate open and slippage, but can not simulate the body of soil microstructure overturning (rolling ). Through particle size continuum mechanics finite element simulation program, we can simulate soil deformation localization in the process of the particle size effect, get the deformation localization process characteristics, study the micro failure mechanism of soil and the intrinsic parameters. In this paper, the test result, the self made program and result of scale effect simulation analysis on soil are great realistic significance to soil engineering management, and disaster prediction.