岩土工程学报Issue(8)：1407-1413,7.DOI:10.11779/CJGE201408005
黏土触变过程中强度恢复的微观机理
Microscopic mechanism of strength increase of clay during thixotropic process
摘要
Abstract
The thixotropy is one of rheological properties, and it is the phenomenon that the strength decreases owing to external force and then gradually increases with time after stopping disturbance. In order to explore the microscopic mechanism of strength increase of clay during thixotropic process, the unconfined compressive strength and penetration resistance of Zhanjiang clay after disturbance of 500 d are tested, the thixotropic strength evolution process is analyzed, and the thixotropic rules are determined according to the thixotropic strength ratio. Furthermore, microstructural change at different standing time is studied using the scanning electron microscope and mercury injection experiment. The results show that the thixotropic characteristics of Zhanjiang clay are significant, and the strength after 500 d is 2.58 times that after the disturbance, but the thixotropic increase strength only accounts for 21.2%~23.5% of the disturbance strength loss. Therefore, for the soils with high sensitivity and strong structure engineering disasters can not be ignored because of strength loss caused by construction disturbance. The thixotropic strength recovery is the result of the structural evolution from dispersion to flocculation through attraction and repulsion between particles owing to change of force field. In this process, the microstructure is self-adapted and pore distribution uniformly develops, and in a certain period of time the thixotropic phenomenon occurs.关键词
黏土/触变/强度/微观结构/机理Key words
clay/thixotropic/strength/microstructure/mechanism分类
建筑与水利引用本文复制引用
张先伟,孔令伟,李峻,杨爱武..黏土触变过程中强度恢复的微观机理[J].岩土工程学报,2014,(8):1407-1413,7.基金项目
国家自然科学基金项目（41102200）；国家自然科学基金项目（51179186）；天津市软土特性与工程环境重点实验室开放课题 （）
