非饱和土二、三维固结方程简化计算方法

针对非饱和土的固结问题的复杂性,为了计算的简化,将非饱和土固结分为3个阶段:初期压密、气压消散和水压消散。假定前两个阶段是瞬间完成的,其后独立考虑水压的消散。分别建立3个阶段的二、三维控制方程,以计算各阶段的气压、水压、骨架应力、相应的土体变形和水量变化。算例的计算结果表明本文方法简便、实用。该简化方法主要适用于饱和度不太高的非饱和土,而对饱和度较高的非饱和土,由于气压消散过程较长,不宜采用。

Two-or three-dimensional simplified consolidation calculation of unsaturated soil

In consideration of the complexity of the consolidation process of unsaturated soil and for simplification of the calculation,the consolidation process was divided into three stages,i.e.compaction at initial period,air pressure dissipation,and water pressure dissipation.It was assumed that the compaction at initial period and air pressure dissipation were completed instantaneously, and the stage of water pressure dissipation was studied separately.Then two-or three-dimensional control equations for the three stages were established respectively for calculation of the air pressure,water pressure,effective stress,soil deformation and variation of water volume.Case study shows that the present method is simple and practical,and that the simplified method is suitable for unsaturated soil with relatively low degree of saturation but not suitable for unsaturated soil with high degree of saturation due to the fact that for such soil the air pressure dissipation lasts a long period of time.