考虑土中指数形式渗流定律以及土体的非线性固结特性,以超静孔隙水压力为变量在拉格朗日坐标系内建立了软土一维大变形固结问题的控制方程及其求解条件,并运用有限差分法获取其数值解答。在指数形式渗流定律退化为达西定律下,通过将差分解与已有的半解析解进行对比,验证了数值计算的可靠性。最后对指数形式渗流定律下软土一维非线性大变形固结性状进行计算分析,结果表明: 1时,软土的非线性大变形固结速率会随外载增大而减慢; 1时,软土的非线性大变形固结速率会随着外荷载的增加而加快;软土非线性大变形固结速率要比非线性小变形固结速率快,且差别会随荷载增大而加剧;此外,大变形固结理论的最终沉降值要小于小变形固结理论,且差别会随着荷载的增大而加剧。
Considering the exponential seepage flow law in soil and the nonlinear consolidation behavior of soil, the equations and solution conditions governing 1 D nonlinear large-strain consolidation, in which the excess pore water pressure served as variable, were founded in Lagrangian coordinates; and its numerical solutions were obtained by finite difference method. On condition that the exponential seepage flow law was degenerated into Darcy’s law; the reliability of numerical solutions was testified by comparing the finite difference solutions to semi-analytical solutions. Finally, the consolidation behavior of 1-D non-linear large strain consolidation with exponential flow law were analyzed; and the results show that the rate of nonlinear large strain consolidation of soft clay slows down with increasing the external load in case of 1, and accelerates with increasing the external load in case of 1. The rate of nonlinear large strain consolidation is faster than that of nonlinear small strain consolidation; and the difference between them may intensify with increasing the external load. Furthermore, the final settlement by the theory of large strain consolidation is smaller than that of small strain consolidation, and the difference between them also may intensify with increasing the external load.