混黏土的粉土、粉砂室内试验液化判别标准的研究

目前对于在循环荷载作用下的混黏土的粉土、粉砂的液化判别还存在着很多问题。根据动三轴试验的结果，对天津地区的混黏土的粉土、粉砂在循环荷载作用下的孔压累积及动变形特性进行了分析研究，对混黏土粉土、粉砂室内试验液化判别的孔压及应变标准进行了探讨。并将现场波速试验与室内试验判别液化的结果相比较。发现对于天津地区的混黏土粉土、粉砂，在循环荷载作用下，孔压达到围压的60 %～80 %，即趋于稳定，相应的全幅应变约为5 %。因此，这两项指标可作为液化的判别标准。

Study of liquefaction evaluation used in indoor test of silt, silty sand mixed clay

No guidelines are available on liquefaction evaluation of silt-clay and silty sand-clay mixtures under cyclic loading. The liquefaction behavior of these kinds of soils is not understood clearly at present. In this paper, according to the results of dynamic triaxial tests, the characters of cumulative pore water pressure and dynamic deformation of silt-clay and silty sand-clay in Tianjin are analyzed. The liquefaction evaluations of indoor tests are studied. At the same time, the results of wave velocity test in situ are compared to that of the indoor tests. As results, for the silt-clay and silty sand-clay in Tianjin under cyclic load, the value of water pore pressure tends to be stable when it is equal to 60 %-80 % of confining pressure; the corresponding value of double amplitude strain is 5 %. Therefore, these values can be used as the indexes of liquefaction evaluation.