基于非保守体力的大变形固结有限元法

FINITE-STRAIN CONSOLIDATION FINITE-ELEMENT METHOD SUBJECT TO NON-CONSERVATIVE BODY FORCE

考虑土体固结过程中体力的非保守特点,完善了T.L.描述的大变形固结平衡方程,并以伴生体力代替非保守体力,提出了相应的大变形固结增量有限元列式.当忽略土体体积应变的影响时,改进的大变形固结平衡方程及其有限元法均可退化为基于保守体力的传统形式.采用自主开发的程序对大变形自重固结算例进行分析,结果初步表明:传统方法低估了地基固结度,但高估了地基沉降量和超静孔隙水压力.基于非保守体力的大变形固结分析在理论上能够更合理地预测地基的固结性状.

Numerical analysis of finite-strain consolidation is investigated by finite element method with non-conservative body force. Firstly, a modified static equilibrium equation for finite-strain consolidation is proposed during the consolidation process of saturated soils using Total Lagrangian description with non- conservative body force. Secondly, the corresponding incremental finite-element （FE））formulations of finite- strain consolidation axe presented with the substitution of the non-conservative body force for a fellow body force. Both the equilibrium equation and the new FE formulations can be reduced to the traditional conservative forms by neglect of the volume strain of soils, respectively. A case of finite-strain self-weight consolidation was presented to study the significance of non-conservative body force. The numerical results show that traditional method underestimates the consolidation degree of foundation, but overestimates the consolidation settlement and excess pore water pressure. The present finite-strain consolidation analysis based on non-conservative body force is available to precisely predict the consolidation behavior of foundation.