点击次数：

论文类型：会议论文

发表时间：2006-01-01

收录刊物：CPCI-S

页面范围：53-58

关键字：Gibbs Free Energy Function; Elastic Component; Anisotropy; Coupling; Triaxial Test

摘要：In the Duncan-Chang E-B model, the unloading-reloading modulus and the bulk modulus are usually defined through the pressure-dependent expression. This model can result in elastic behavior that violates the laws of thermodynamics. To guarantee that an elasticity model is thermodynamically acceptable it must be possible to derive the elastic behavior from a free energy potential. Based on contribution of elastic bulk modulus and elastic shear modulus to Gibbs free energy function, formulate elastic component of Gibbs free energy function for soils from the elastic component of Duncan-Chang E-B model. Then obtain the incremental stress-strain relationship by use of the Legendre transformation. A very important result of this approach is that it automatically implies stress-induced cross-anisotropy and dilatancy term occurs due to shear modulus dependency on pressure. Proper modeling of these phenomena is normally neglected by conventional models. The computational results of several closed-loop stress paths indicate that modified model automatically satisfy the requirement that the elastic response for any loading path be energy conserving. Moreover, the elastic responses predicted by modified model are compared with the undrained and drained triaxial tests under the different consolidation pressures in order to assess the predictive capability. In each case good agreement with experiment is obtained.