Study On Finite Characteristic Ratio Theory Constitutive Model For Mud

Some classical elastic and plastic theories are adopted, or some traditional plastic theories considering Darcy's law are recommended to study soil constitutive models. To some more complicated things, cohesive and plastic models, hypoplasticity models and so on are used to character the deformation of soil particle. When talking about the characters of several media with continuous media theory and thermodynamics of continuous media, the finite geometry point is not considered, which is challenged in charactering the material of sock and soil. The test of sock shows that material deformation and strength has important relation with its internal grain dimensions. It is pointed out that the grain dimensions and shape may be the most influencing factor to soil deformation.The finite characteristic ratio, which is the ratio of a material intemal characteristic measurement to the material extemal characteristic measurement, is a basic phenomenological variable which is put forward by Zhangming Li. Base on the irreversible thermodynamics, The finite characteristic ratio theory (FCRT) was built, which start from the finite characteristic ratio.The theory of the finite characteristic ratio method can character material irreversible deformation. It can be also used to character stain localization. In this thesis, the FCRT constitutive model of mud is determined to character the deformation of mud. The elaborate work involves several aspects as follow:(1). Mud is tested with the automated triaxial compression test system. Two projects are adopted. One is mud which was got from the same place(mud with the same grain size)with but different confining pressure and different test types, the other is different soil with same external measurement, same confining pressure and same test types. The study is the change of stress (total stress and effective stress), the change of pore pressure, the change of volume and the reaction of stress and deformation with different confining pressure. On the base of the results, the structural characteristics and the mechanical characteristics of mud has been discussed.(2). Based on Zhangming Li's FCRT and combined with the test, the evolution of mud is founded and the FCRT constitutive model is determined through the method of back-analysis and curve simulation. Through the comparison of the results of FCRT constitutive model and the test, it is found that the results and their curve is consistent. It shows that FCRT constitutive is reasonable to character the deformation of mud.(3). Through the comparison of the results of FCRT constitutive model of mud and sand with different grain size and the results of the automated triaxial compression test which were got from Haiyan Jv's study and this thesis, it can be draw that FCRT can be more accuracy and reasonable when the configuration characteristics between inside and outside is more distinct than the typical elastic plastic constitutive models. It is also can bu draw that the FCRT can back to typical elastic plastic constitutive models when the effect of the finite characteristics ratio is ignored. Finally, through the data about displacement of actual project which were calculated through FCRT, D-P model and Cam-clay model and the data which was got from the test on-site, it can be concluded that the more accuracy results can be got when FCRT used in actual project than D-P model and Cam-clay model, so the rationality of FCRT theory to actual project can be proved.