非饱和土的一种分类方法

根据理想模型中土颗粒和孔隙水之间的几何关系、热力学原理和土力学基本理论,研究了土的非饱和性在非饱和土中引起的力系。给出了张力吸力和吸力比的定义,并在考虑基质吸力作用面积的基础上定义了等效吸力的概念。按照孔隙水弯液面是否与土颗粒表面搭接,将非饱和土分为搭接非饱和土和不搭接非饱和土两类。进而根据搭接状态将搭接非饱和土细分为水封闭非饱和土和搭接双开敞非饱和土,根据孔隙气状态将不搭接非饱和土细分为不搭接双开敞非饱和土和气封闭非饱和土。在搭接非饱和土中,出现张力吸力并对土体的强度产生增强作用;在不搭接非饱和土中,表面张力只是沿着液面传播,不对土的强度产生效应。另外,张力吸力只对强度问题有贡献,它不是渗流问题的驱动力。

Classification for Unsaturated Soils by Overlapping State of Pore Water

Based on thermodynamics theory and foundational principle of soil mechanics,geometrical relation between ball-shaped particles and pore water is employed to investigate the force system in unsaturated soils induced by unsaturation.And then definitions for tension suction and suction ratio are construted.Another concept named equivalent suction is put forward after magnitude of suction as well as correspondiog effective area of matric suction and tension suction on particle surface are taken into consideration.Study on an ideal model shows unsaturated soils can be rationally divided into overlapping unsaturated soils and non-overlapping unsaturated soils according to whether meniscus overlaps on particle surface or not.Tension suction only appears in overlapping unsaturated soils and contributes to strength but not to seepage is another achieved conclusion.