Research On Transitional Fines Content Of Sand And Silt Mixtures And Constitutive Model

The study on constitutive models is a significant topic in the research of GeotechnicalEngineer. The effective way to judge a constitutive model can truly reflect the influence ofstress route is whether or not it can describe the relations between stress and strain, also it’slimit stress ratio under different situations with reason. The existing constitutive modelsmostly based on drainage conditions, which can not predict the relation between stress andstrain under the situations without drainage condition reasonably. Therefore, it is verysignificant that build a constitutive model which truly reflect the influence of stress route andlimit stress ratio.The article introduced the main physical-mechanical properties of Nanjing sand, bypointing out the meaning of study on the undrained characteristics and the drainedcharacteristics of Nanjing sand. Researching the critical fine grain content of sand-siltmixtures has certain practical significance.The article summarizes the study and development on constitutive model of soil body,illustrating the significance of such constitutive model. This article also had discussed thecharacteristics of soil deformation by the numbers, and the intensive study of incrementaltheory of plasticity, which provide the theory base of constitutive model of soil.On the basis study of superior sand model, referring to asymptotic behavior model, Ireconstruct a hardening parameter, which can be distributed into two classes: couplinghardening parameter and uncoupling hardening parameter. The new a conclusion ofconstitutive equation was deduced by confirming yield function and plastic potential function.Adopting the theory of experimentation prediction, the sensitivity analysis of the parametricvariation in this constitutive model can obtain a result including the major parameter andminor parameter affecting the variation of constitutive model. In CU tests, the analysis onsome particular characteristics compared with the result from the prediction of constitutivemodel, which verified the accuracy of this model under the CU tests.