纯主应力轴旋转下饱和软黏土的循环弱化及非共轴性

钱建固; 杜子博

doi:10.11779/CJGE201608004

纯主应力轴旋转下饱和软黏土的循环弱化及非共轴性 English Version

钱建固^{1, 2},
杜子博^{1, 2}

1. 同济大学地下建筑与工程系,上海 200092; 2. 同济大学岩土及地下工程教育部重点实验室,上海 200092

基金项目: 国家自然科学基金项目（41272291,51238009,51578413）

详细信息

作者简介:
钱建固(1972- ),男,教授,博士生导师,从事软土力学与本构理论研究。E-mail: qianjiangu@tongji.edu.cn。

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- 文章访问数: 436
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出版历程
- 收稿日期: 2015-07-23
- 发布日期: 2016-08-24

Cyclic degradation and non-coaxiality of saturated soft clay subjected to pure rotation of principal stress axis

QIAN Jian-gu^{1, 2},
DU Zi-bo^{1, 2}

1. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 2. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China

摘要

摘要: 采用空心圆柱扭剪仪对原状饱和软黏土进行了纯主应力轴旋转应力路径的循环不排水试验,加载过程中维持平均应力、广义剪应力和中主应力系数不变。观测了孔隙水压和各应变分量在循环加载过程中的变化特性,着重探讨了中主应力系数及广义剪应力对变形刚度以及非共轴特性的影响规律。主应力偏转的循环剪切路径下,存在扭转剪切和轴向剪切两种不同的循环应力应变响应。试验结果表明：循环加载路径下饱和软黏土的孔压及应变产生累积效应,应力应变刚度呈现各向异性弱（强）化效应,而应变增量呈现显著的非共轴性;中主应力系数b影响特性表现为,b值越大则刚度弱化越显著。试验观察还发现,剪应力水平较低时循环变形刚度表现为强化,非共轴角趋于增大;反之,剪应力水平较高时,伴随着循环弱化,非共轴角趋于减小。
- 主应力轴旋转 /
- 循环弱化 /
- 非共轴 /
- 各向异性 /
- 饱和黏土
Abstract: A series of cyclic undrained tests on saturated soft clay subjected to pure rotation of the principal stress axis are conducted using the hollow cylinder apparatus (HCA). The magnitudes of the mean principal stress and the generalized shear stress as well as those of the intermediate principal stress parameter are kept constant during cyclic loading. The development rules of pore water pressure and strain components during loading are studied. Specifically, the effects of the intermediate principal stress parameter and the generalized shear stress level on the stiffness of stress-strain as well as non-coaxiality are addressed. During the cyclic rotation of the principal stress axis, two distinct cyclic shear responses, i.e., torsional shear stress-strain and shear stress-strain responses, are activated. The experimental observations show that along the cyclic loading path, the pore pressure and the strain accumulated. Meanwhile, the shear stiffness over stress-strain loops exhibits an anisotropic cyclic degradation, and the strain rate is manifested as non-coaxiality. As for the effect of intermediate principal stress parameter b, the stiffness decreases with the increasing value of b. It is also found that the non-coaxial angle increases with growing stiffness at a low shear stress level. Inversely, the stiffness reduction and non-coaxial angle increase are observed at a high shear stress level.
- principal stress axis rotation /
- cyclic degradation /
- non-coaxiality /
- anisotropy /
- saturated clay

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参考文献(29)

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文章访问数: 436
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纯主应力轴旋转下饱和软黏土的循环弱化及非共轴性 English Version

作者简介: 钱建固(1972- ),男,教授,博士生导师,从事软土力学与本构理论研究。E-mail: qianjiangu@tongji.edu.cn。

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Cyclic degradation and non-coaxiality of saturated soft clay subjected to pure rotation of principal stress axis

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目录

作者简介:
钱建固(1972- ),男,教授,博士生导师,从事软土力学与本构理论研究。E-mail: qianjiangu@tongji.edu.cn。