双向激振循环荷载和振动频率共同作用下饱和软黏土孔压试验研究

发布时间：2018-04-04 09:40

本文选题：宁波黏土　切入点：循环应力比　出处：《岩土工程学报》2017年S2期

【摘要】：利用GDS变围压动三轴试验系统模拟真实交通荷载下轴向循环正应力与水平循环正应力的耦合作用,对宁波饱和重塑软黏土进行一系列变围压不排水循环加载试验,对循环轴向偏应力和循环围压耦合作用下饱和软黏土的孔压变化规律进行了研究,分析了循环应力比、循环围压及振动频率对孔压的影响。研究结果表明:变围压作用下,孔压随循环应力比、循环围压的增加而增大,随振动频率的增加而减小。不同应力路径斜率、振动频率影响下,孔压率随加载时间的变化规律一致,循环应力比CSR、应力路径斜率η对孔压率时间关系影响明显,随着循环应力比CSR、应力路径斜率η的增大,孔压率也增大,而振动频率对孔压率时间关系影响不显著。在上述试验结果基础上得知,估算交通荷载作用下产生的孔压,不能忽视循环围压及振动频率的影响。
[Abstract]:The coupling of axial cyclic normal stress and horizontal cyclic normal stress under real traffic load is simulated by GDS variable confining dynamic triaxial test system. A series of undrained cyclic loading tests on Ningbo saturated remolded soft clay are carried out.The variation of pore pressure of saturated soft clay under cyclic axial deflection stress and cyclic confining pressure coupling is studied. The effects of cyclic stress ratio, cyclic confining pressure and vibration frequency on pore pressure are analyzed.The results show that the pore pressure increases with the increase of cyclic stress ratio and decreases with the increase of vibration frequency.Under the influence of different stress path slope and vibration frequency, the variation of pore pressure ratio with loading time is consistent. The cyclic stress ratio CSR and stress path slope 畏 have obvious influence on the relationship between pore pressure and time.With the ratio of cyclic stress to CSR, the slope 畏 of stress path increases and the pore pressure ratio increases. However, the vibration frequency has no significant effect on the relationship between pore pressure and time.On the basis of the above experimental results, it is found that the influence of circulating confining pressure and vibration frequency can not be ignored in estimating the pore pressure under traffic load.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;中国科学院大学;武汉市市政建设集团有限公司;武汉地铁集团有限公司;
【基金】：国家重点基础研究发展计划(“973”)项目(2015CB057905) 中国科学院科技服务网络计划(STS)(KFJ-EW-STS-122) NSFC-云南联合基金重点支持项目(U1402231)
【分类号】：TU41

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