细粒含量对粉土动孔压发展模式影响的试验研究

采用多功能静动液压剪切仪进行了粉土动荷载下的孔压试验,探讨了黏粒含量和粉粒含量对重塑粉土动孔压发展的影响.试验模拟大震时细粒含量影响的孔压发展规律,对已有的指数形式孔压模式进行修正,以便模拟初始液化发生后达到一定液化程度的实际情况,该模式包含2个参数a和b.研究结果表明,细粒含量对粉土动孔压发展影响较大,其影响主要体现在孔压发展模式参数b上.粉土中粉粒含量与孔压参数b的关系呈单调的线性关系,而黏粒含量与孔压参数b的关系则不是单调的线性关系,是在黏粒含量为8 %时孔压参数b达到的最大值,试验数据验证该修正的动孔压模式有更广泛的应用性.

Test study on influence of fine particle content on dynamic pore water pressure development mode of silt

Laboratory tests on dynamic pore water pressure of silty soils are carried out in a new universal triaxial torsional shear apparatus of Hohai University. The influence of clay particle content and silt particle content on dynamic pore water pressure of disturbed silty soil is concluded. The mode of dynamic pore water pressure of silty soil can be expressed in a modified exponential function with two parameters a and b to simulate the severity of liquefaction after initial liquefaction. It is found that fines content has great effect on the dynamic pore water pressure of silt by the parameter b. The relationship between parameter b and silt particle content is linear, while the relationship between parameter b and clay particle content isn’t linear which reaches the maximum value when the clay content is 8 %. It is validated that modified dynamic pore water pressure mode has widely application by many tests data from both the author’s and others’.