土体自重沉降模型研究与求解

Research and solution of self-weight sedimentation model of soils

在Gibson土体大变形固结方程基础上,以孔隙比为控制变量,假定在欧拉坐标系下土颗粒静水沉降过程中有效应力为零,推导了土颗粒静水沉降公式.采用特征方程法,得到了悬浮液-清水界面下降公式以及在沉降过程中沉积层孔隙比计算公式,并采用激波理论进行解释.分析结果表明,在悬浮液-清水界面与沉积层-悬浮液界面相遇之前,悬浮液的孔隙比保持常数,而沉积层的密度和孔隙比以激波形式沿深度发生变化.采用特征方程法求解得到的孔隙比计算公式能够较好地解释混合物沉降过程.将沉积层密度与孔隙比随时间空间变化规律与文献试验现象进行对比,得到了较为满意的结果.

Based on the large deformation consolidation equation of Gibson, regarding the void ratio as control variable, the settlement formula of soil particles in steady water was derived on the assumption that the effective stress was zero during the settling process in the Eulerian coordinate. According to the characteristic equation of the settlement formula, the decline formula of the interface between suspension and water and the formula of void ratio of deposition layer were also obtained, then the shock-wave theory was used to explain the phenomena： Analysis shows that the void ratio of the suspension is constant while the density and void ratio of the deposition layer change in the form of shock wave with the depth before the suspension-water interface meets with the deposition layer-suspension interface. The void ratio formula deduced by the characteristic equation method can explain the mixture settlement process. Comparisons of the distributions of density and void ratio in the deposition layer with the existing test results obtained satisfied results.