Fully coupled global equations are proposed for enhancing the performance of Finite Element analysis of unsaturated soils. The governing equation describing mechanical equilibrium is formulated in terms of net stress, and in the mass conservation equation the contribution of this net stress in determining the change of degree of saturation is also included. The novelty of this paper is the development of new global finite element equations that can be used to find an approximate solution to these governing equations. The new equations have a mechanical term appearing in the flow matrix that is additional to the usual hydraulic term. This is in contrast to previous studies in which the coupling matrices ignore this effect. A performance study has been conducted for undrained footing problems, which shows that the additional mechanical term appearing in the flow matrix has a large influence on the accuracy of the numerical results.

中文翻译：

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非饱和土水力学分析的全耦合全局方程

提出了完全耦合的全局方程来提高非饱和土的有限元分析的性能。描述机械平衡的控制方程用净应力表示，在质量守恒方程中，该净应力对确定饱和度变化的贡献也包括在内。本文的新颖之处在于开发了新的全局有限元方程，可用于找到这些控制方程的近似解。新方程有一个机械项出现在流动矩阵中，它是通常的水力项的补充。这与之前的研究相反，在这些研究中，耦合矩阵忽略了这种影响。对不排水地基问题进行了性能研究，