软黏土地基土体抗剪强度若干问题

Some problems concerning shear strength of soil in soft clay ground

针对不少土力学教材和规范规程认为由UU试验得到的是饱和黏性土的抗剪强度指标,将黏性土不排水抗剪强度视为土的抗剪强度指标的错误概念,首先分析了土的抗剪强度和抗剪强度指标之间的区别,然后通过分析三轴固结不排水剪切试验和土的抗剪强度指标的测定,三轴不固结不排水剪切试验和土的不排水抗剪强度的测定,讨论了黏性土不排水抗剪强度和抗剪强度指标之间的区别。通过软黏土地基中土体的抗剪强度及测定方法的讨论,再次说明了黏性土不排水抗剪强度和抗剪强度指标之间的区别。最后提出岩土工程稳定分析四者相匹配原则。通过讨论分析,澄清了一些模糊概念,有利于提高岩土工程分析水平。

Some concepts of shear strength and shear strength parameter,undrained shear strength and unconsolidated-undrained triaxial test are wrong in some soil mechanics textbooks and geotechnical engineering codes.The differences between the shear strength and the shear strength parameter are firstly discussed.Then the shear strength parameters determined by means of the consolidated undrained triaxial tests and the undrained shear strength determined by unconsolidated-undrained triaxial tests are analyzed.The differences between the undrained shear strength and the shear strength parameter of the soft clay are discussed.With the discussion about determination of the shear strength in the soft clay ground,the differences between the undrained shear strength and the shear strength parameter of the soft clay are discussed again.Finally,the stability analysis method,calculation parameters,determination method of calculation parameters and safety factor are coincided in the stability analysis of geotechnical engineering.