A LIQUEFACTION TEST WITHOUT MEMBRANE PENETRATION EFFECTS
A LIQUEFACTION TEST WITHOUT MEMBRANE PENETRATION EFFECTS
复制标题
无膜穿透效应的液化测试
DOI：
10.3208/sandf1972.26.4_127
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发表时间：
1986
影响因子：
3.7
通讯作者：
K. Nakamura
中科院分区：
文献类型：
--
作者：
K. Tokimatsu;K. Nakamura
摘要设计了一种试验系统，以最大限度地减少膜渗透对颗粒土不排水剪切强度的不利影响。组成电-气闭环系统的系统可以实时补偿膜穿透引起的体积变化，从而保持土体骨架体积的恒定。它可以很容易地连接到任何传统的静力或循环剪切试验设备。为了评价该系统的有效性，对直径75 mm的试件进行了有无该系统的循环三轴试验。比较了有膜柔度试件和无膜柔度试件的孔压响应和液化强度曲线，并讨论了膜渗透的影响。试验结果表明，对于平均粒径为0.17 mm的细砂，膜渗透对其液化特性影响不大，而对于平均粒径为1 mm的粗砂，由于膜的渗透，导致液化的循环剪应力比被高估了约30%。这些结果与其他研究人员的分析估计是一致的，表明该系统在液化试验中的性能令人满意。
ABSTRACT A test system is devised to minimize detrimental effects of membrane penetration on the undrained shear strength of granular soils. The system constituting an electropneumatic closed-loop can compensate for volume changes caused by membrane penetration in real time so that the constant volume of soil skeleton is maintained. It can readily be coupled to any conventional static or cyclic shear test apparatus. In order to evaluate effectiveness of the system, cyclic triaxial tests were performed on specimens 75 mm in diameter either with or without the system. Resulting pore pressure responses and liquefaction strength curves for specimens with and without membrane compliance are compared, and the effects of membrane penetration are discussed. The test results revealed that, while the liquefaction characteristics of a fine sand with a mean grain size of 0.17 mm were not affected significantly by membrane penetration, the cyclic shear stress ratios to cause liquefaction for a coarse sand with a mean grain size of 1 mm were overestimated by about 30% as a result of membrane penetration. These results are consistent with an analytical estimation by other investigators, indicating satisfactory performance of the system in liquefaction tests.