基坑开挖过程中TJ-1模拟月壤变形特性的试验研究  

Deformation behaviors of TJ-1 lunar soil simulant during excavation

作　　者：蒋明镜[1,2] 李立青[1,2] 刘芳[1,2] 苏佳兴[1,2] 

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]同济大学地下建筑与工程系,上海200092

出　　处：《岩土工程学报》2012年第7期1176-1183,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家杰出青年基金项目(51025932);国家自然科学基金项目(10972158;51179128);上海市优秀学术带头人计划(11XD1405200)

摘　　要：采用空心圆柱扭剪仪对TJ-1模拟月壤试样进行基坑开挖应力路径的试验模拟,以研究地球重力场环境下TJ-1模拟月壤在地基开挖过程中的变形及非共轴特性。试验结果表明:应力路径对TJ-1模拟月壤的变形影响显著;开挖过程中坑底及连续墙外侧模拟月壤因变形过大而破坏,坑底位置土体受连续墙挤压的影响发生明显的剪缩现象;连续墙内外土体明显的非共轴现象是开挖所致偏应力、应力主轴转幅及旋转速率耦合作用的结果,且上述因素在不同位置影响程度也不相同,坑底位置以应力主轴的转幅及旋转速率的影响为主,基坑外侧则是偏应力比、转幅及旋转速率共同作用的结果。Torsion shear tests are conducted by use of a dynamic hollow cylinder apparatus in Tongji University on the T J-1 lunar soil simulant subjected to stress paths of excavation in order to investigate its deformation behaviors and non-coaxiality during the excavation under the earth environment. The test results indicate that （1） the stress path significantly affects the deformation behaviors of the TJ-1 lunar soil simulant; （2） the soils at the bottom of the pit and outside the diaphragm walls fail due to large deformation; （3） the soils at the bottom exhibit a tendency of contraction; （4） the soils adjacent to the diaphragm walls show remarkable non-coaxiality due to the coupled effects of stress ratio, rotation amplitude and rotation rate of the principal stress; and （5） the non-coaxiality of soils at the bottom of the pit is mainly affected by the rotation amplitude and rotation rate of the principal stress direction, while the non-coaxiality of soils outside the wall is controlled by the stress ratio, rotation amplitude and rotation rate of the principal stress direction.

关 键 词：TJ-1模拟月壤 基坑开挖 应力路径 空心圆柱扭剪仪 变形特性 非共轴 

分 类 号：TU411[建筑科学—岩土工程]