摘要
采用散粒材料的宏细观力学分析方法,在颗粒水平研究砂土的诱发各向异性强度特性,提出了砂土各向同性与应力诱发各向异性强度的区别与联系,从细观机理上将二者区分开来。分析了M-C、M-N、L-D三种强度准则在考虑诱发各向异性方面的差异,基于三轴压缩与三轴伸长破坏各向异性发展的不同,建立了考虑中主应力影响的简单破坏应力比–组构关系。从微细观角度建立了砂土应力诱发各向异性强度准则,并考虑了砂土不同密实状态对诱发各向异性强度的影响,最后与已有的真三轴试验结果进行了比较分析。研究结果表明:建立的诱发各向异性强度准则,物理参数意义较明确,与试验结果吻合较好,有助于从微细观机理分析砂土的各向异性强度特征。
Stress-induced anisotropic strength of sand is analyzed on the particle level based on the micromechanics of granular. The differences between the isotropic strength and the stress-induced anisotropic strength are discussed from the viewpoint of micro-mechanism. Three classical strength theories, namely, M-C, M-N, L-D criteria, are discussed from the aspect of stress-induced anisotropy. Based on different anisotropies developed under triaxial compression and triaxial tensile stress condition, a simple fabric-stress relationship is proposed considering the effect of intermediate principal stress. A micromechanics-based stress-induced anisotropy strength criterion is developed to simulate the macro-mechanical response of real sand considering the effect of density state. Finally, several sets of true triaxial tests are chosen to be compared with the predicted results from the proposed strength criterion. The numerical results indicate that the proposed strength criterion, whose parameters have clear physical meanings, presents an effective approach to analyze the induced anisotropic strength characteristics of sand from the microscopic mechanism.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2013年第3期460-468,共9页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51178044)
新世纪优秀人才资助项目(NCET-11-0579)
作者简介
作者简介： 刘 洋（1979- ），男，江苏徐州人，博士，副教授，主要从事土细观力学和砂土液化方面的研究与教学工作。E-mail： ly-ocean@sohu.com。
