Undrained cyclic triaxial behavior of saturated clays under variable confining pressure
Undrained cyclic triaxial behavior of saturated clays under variable confining pressure
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DOI：
10.1016/j.soildyn.2012.03.011
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发表时间：
2012-09
影响因子：
4
通讯作者：
C. Gu;Jun Wang;Yuanqiang Cai;Zhongxuan Yang;Yufeng Gao
中科院分区：
文献类型：
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作者：
C. Gu;Jun Wang;Yuanqiang Cai;Zhongxuan Yang;Yufeng Gao
通过室内试验研究了饱和粘土在变围压条件下的不排水动力特性。利用动三轴仪对重塑粘土样进行了试验，动三轴仪的偏应力和围压可以同时变化。通过改变循环偏应力与循环围压的比值或相位差，在试件上施加不同的循环应力路径。具体而言，在本研究中使用的应力路径的设计，以模拟由于地震和其他振动源的粘土中的同时变化的剪切应力和正应力的耦合效应。试验结果表明，围压的变化对饱和粘土的不排水响应有很大的影响，包括孔隙水压力、循环应变发展速度和循环强度的大小。结果表明，当土层中存在较强的P波时，VCP试验比常规的恒围压循环三轴试验（CCP试验）更适合于地应力场的模拟。
A laboratory study on the undrained dynamic behavior of saturated clays in cyclic triaxial tests with a variable confining pressure (VCP tests) is presented. Tests were performed on remolded clayey samples using a dynamic triaxial device where the deviatoric stress and confining pressure can be varied simultaneously. Various cyclic stress paths have been applied on the specimens through varying the ratios or phase differences between the cyclic deviatoric stress and cyclic confining pressure. Specifically, the stress paths used in the present study were designed to simulate the coupling effects of simultaneously varying shear and normal stresses in clays due to earthquakes and other vibration sources. Test results obtained from this study show that the undrained response of saturated clays is strongly influenced by the variation of confining pressure, in terms of pore water pressure, development speed of cyclic strain and magnitude of cyclic strength. It is found that when strong P-waves are propagating in soil layers, VCP tests are more appropriate for the simulation of in situ stress fields than the conventional cyclic triaxial tests with a constant confining pressure (CCP tests).