主应力轴纯旋转条件下原状黏土变形特性研究

严佳佳; 周建; 龚晓南; 郑鸿镔

doi:10.11779/CJGE201403010

主应力轴纯旋转条件下原状黏土变形特性研究 English Version

1. 浙江大学滨海和城市岩土工程研究中心,浙江杭州 310058; 2. 宁波万科房地产开发有限公司,浙江宁波 315000

基金项目: 国家自然科学基金项目（50778162; 51178422; 51078329）

详细信息

作者简介:
严佳佳(1986- )，男，浙江余杭人，博士研究生，主要从事复杂应力路径条件下软黏土工程特性的试验和本构模拟方面的研究。E-mail: yanjia.01@163.com。

通讯作者:
周建

中图分类号: TU47
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出版历程
- 收稿日期: 2013-06-20
- 发布日期: 2014-03-19

Deformation behavior of intact clay under pure principal stress rotation

1. Research Center of Coastal and Urban Geotechnical Engineering of Zhejiang University, Hangzhou 310058, China; 2. Ningbo Vanke Real Estate Development Co., Ltd., Ningbo 315000, China

摘要

摘要: 采用空心圆柱扭剪仪对原状软黏土进行了不排水条件下的主应力轴纯旋转试验,即主应力轴旋转过程中平均主应力、剪应力和中主应力系数都保持不变。重点研究了中主应力系数对原状软黏土在主应力轴纯旋转条件下的孔压和变形特性的影响,基于试验结果对主应力轴纯旋转的影响机理进行了分析。试验结果表明：即使3个主应力的值都保持不变,原状黏土的孔压和应变也会随着主应力方向的旋转而累积,经历主应力轴的旋转后土体刚度减小；主应力轴连续旋转时主应变增量方向与主应力方向存在显著的非共轴现象；中主应力系数对主应力轴旋转条件下孔压和应变的开展以及刚度衰减有显著的影响,而对非共轴特性的影响较小。电镜扫描结果表明经历主应力轴旋转后黏土颗粒破碎聚集成较大的团粒,大孔隙显著减少,颗粒和孔隙分布趋于均匀,主应力轴旋转的影响机理可以归结为主应力轴旋转对土体微观结构的扰动和破坏。
- 主应力轴纯旋转 /
- 原状黏土 /
- 中主应力系数 /
- 非共轴 /
- 微观结构
Abstract: In this study, a series of undrained pure principal stress rotation tests on intact clay are carried out by use of a hollow cylinder apparatus. The magnitudes of the mean principal stress, shear stress and intermediate principal stress coefficient are kept constant during the principal stress rotation. The influence of the intermediate principal stress on pore water pressure and deformation behavior is studied in particular. The mechanism of the effect of the principal stress rotation is analyzed. The test results show that the pore pressure and strain of intact clay accumulate with the principal stress rotation even when the three principal stresses are kept constant. The directions of the principal strain increment and the principal stress are not coaxial. The influence of the intermediate principal stress coefficient on pore pressure and strain accumulation as well as stiffness degradation is significant, but not obvious on the non-coaxial behavior. The mechanism of the effect of the principal stress rotation can be attributed to the disturbance of the microstructure of intact clay.
- principal stress rotation /
- intact clay /
- intermediate principal stress coefficient /
- non-coaxiality /
- micro-structure

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参考文献(26)

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