非饱和土的抗剪强度理论研究

从孔隙水的存在状态出发 ,围绕Bishop抗剪强度公式中存在的几个疑点展开讨论 .认为非饱和土中支配强度和变形的应力之所以不同 ,是因为非饱和土中存在一种性质与有效应力不同的应力———内部应力 ,它不传递 ,仅影响土的塑性变形 .同时还对Bishop ,Fredlund和卢肇钧提出的抗剪强度公式中的参数测试方法进行分析 ,指出 :各种抗剪强度理论在概念上都是相同的 ,其区别仅在于确定由吸力产生的那部分有效应力时采用的参数和测试方法不同

Research of shear strength theories of unsaturated soil

Based on the state of existence of pore water in soil, some doubtful points about Bishop's formula are discussed. A problem is clarified: the reason why the stresses that determine the strength and deformation of unsaturated soil are different is that an inner stress, different from effective stress, exists in unsaturated soil, which can not be transferred, but only affects plastic deformation. In addition, the parameter test methods of shear strength theories proposed by Fredlund, Bishop, and LU Zhao jun are discussed. It is pointed out that the shear strength theories are identical in concept, and that the difference between the theories lies in different test methods and parameters used in determination of the effective stresses induced by suction pressure.