双层砂井地基大变形固结方程差分解

基于砂井地基轴对称大变形固结控制方程，综合考虑双层砂井地基软土的压缩性与渗透性非线性幂函数变化、分级加荷、径向与竖向同时渗流排水、初始超静孔压几种分布模式等实际条件，采用交替方向隐式（ADI）差分法编程求解了建立的双层砂井地基大变形固结控制方程，通过算例分析验证了建立的方程与差分解法及编制程序的合理性。将本文方法应用于围海造陆工程吹填淤泥与海相沉积淤泥组成的双层砂井地基固结计算，预测的固结沉降过程较经典固结理论更接近于实测值，对双层砂井地基固结沉降过程预测进行了有益的探讨。

Finite difference solution to equation for large-strain consolidation of double-layered vertical drain ground

Based on the governing equation for axisymmetric large-strain consolidation of vertical drain ground, some actual conditions are considered for double-layered sand drain ground, including nonlinear and power function variation of compressibility and permeability of soft clay, stage loading, radial and vertical drainage conditions and several kinds of distribution modes of the initial excess pore pressure. An equation for large-strain consolidation of double-layered vertical drain ground is established, and the alternation direction implicit (ADI) method of finite difference method is adopted to solve the governing equation by means of the computing program. The rationality of the established equation, the finite difference method solution and the computing program are verified through a case study. Compared with the classical consolidation theory, the consolidation settlement process of double-layered vertical sand ground of dredged fill and marine deposit silt in reclamation land projects obtained by the proposed method based on the observed data is more reasonable. A beneficial discussion of predicting the consolidation settlement process of the double-layered vertical sand ground is performed.