列车荷载下考虑频率影响的软黏土破坏标准研究

发布时间：2018-03-01 05:29

本文关键词： 列车荷载重塑软黏土振动频率破坏标准动强度　出处：《岩土工程学报》2017年S1期 　论文类型：期刊论文

【摘要】：列车荷载在地基土体中引发一种心形线主应力轴旋转动力路径,考虑频率作用时,会对地基土产生更为复杂的影响。以南京河西典型重塑软黏土为对象开展数组不同频率f和动应力比η的不排水空心扭剪试验。试验发现,不同动应力比下,土体变形随振动频率的变化趋势主要分为两种情况。另外,随着频率f的提高,试样发生破坏的临界动应力比η'先减小后增大。频率f在1.0~2.0 Hz范围内,孔压发展曲线受频率影响较小,当f=0.5 Hz时,孔压发展显著增大。提出一种适用于列车荷载下考虑频率影响的重塑软黏土破坏评价方法。该标准以孔压应变耦合曲线为主要辨识曲线,可以判别试样所属的稳定、临界或破坏型状态,为后续开展列车荷载引起的软黏土地基承载力研究提供理论支持。
[Abstract]:The train load causes a kind of rotating dynamic path of the principal stress axis of the heart-line in the foundation soil, considering the effect of the frequency, Taking typical remolded soft clay in Hexi, Nanjing as an object, the undrained hollow torsional shear tests with different frequency f and dynamic stress ratio 畏 are carried out. The variation trend of soil deformation with vibration frequency is mainly divided into two situations. In addition, with the increase of frequency f, the critical dynamic stress ratio 畏 'decreases first and then increases. The frequency f is in the range of 1.0 ~ 2.0 Hz. The development curve of pore pressure is less affected by frequency, when f0. 5 Hz, A method for evaluating the failure of remolded soft clay under train load considering frequency is proposed. The main identification curve is the coupling curve of pore pressure and strain, which can be used to judge the stability of the sample. The critical or destructive state provides theoretical support for further research on the bearing capacity of soft clay foundation caused by train load.
【作者单位】：河海大学岩土力学与堤坝工程教育部重点实验室;济南轨道交通集团有限公司;
【基金】：国家自然科学基金面上项目(51479060) 中央高校基本科研业务费专项资金项目(2015B28214) 山东省住房与城乡建设厅科技项目(2014QG009)
【分类号】：TU447;U213.1

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