基于EVP模型的饱和黏性土一维流变固结模型

One-dimensional rheological consolidation of saturated clay based on EVP constitutive model

为深入探讨饱和黏土的固结机理,引入弹黏塑性(EVP)本构模型描述土体的流变固结特性,用Hansbo渗流方程描述土体的渗流过程,修正饱和黏土一维固结理论,采用有限差分法进行求解.通过与文献中固结试验结果的对比,证明了EVP本构模型和本计算方法的有效性,并讨论了Hansbo渗流参数和EVP模型参数对流变固结过程的影响.结果表明,饱和黏土的黏滞效应导致靠近不排水面处在流变固结前期出现了孔压升高现象,Hansbo渗流会使该现象更加明显.饱和黏土的黏滞效应和渗流的非达西特性延缓了固结中后期的整体孔压消散和地基沉降.

To further investigate the consolidation mechanism of saturated clay,the elastic visco-plastic(EVP)constitutive model was introduced to describe the elastic visco-plasticity of saturated clay soils,and the Hansbo’s flow formula for the non-Darcy flow used to describe the water flow through pores in the consolidation process.Terzaghi’s one-dimensional consolidation theory of saturated clay was modified,and a numerical analysis performed by using the finite difference method.To verify the EVP constitutive model and this method,numerical solutions by the present method were compared with the results of rheological consolidation tests in the literature.On this basis,the influences of Hansbo’s flow parameters and EVP model parameters on the rheological consolidation process were explored.The calculated results showed that the viscous effect of saturated clay led to increase in the excess pore water pressure near the undrained boundary in the early stage of rheological consolidation,and the Hansbo flow rendered the phenomenon more obvious.The viscous effect of saturated clay and the non-Darcy characteristic of flow delayed the dissipation of excess pore water pressure for the entire depth of the clay layer and for the ground settlement in the middle and later stages of rheological consolidation.