吹填超软土浅层真空预压加固处理前后的固结特性  

Consolidation property of ultra soft soils before and after treatment of surface-layer improvement by vacuum preloading

作　　者：雷华阳[1,2,3] 张文振[1] 韩鹏[1] 黄茂松[3] 王学超[1] 陈丽[1] 

机构地区：[1]天津大学土木工程系,天津300072 [2]天津大学滨海土木工程结构与安全教育部重点实验室,天津300072 [3]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土工程学报》2013年第12期2328-2333,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51078262);国家重点基础研究发展计划(973计划)项目(2010CB732106);同济大学岩土及地下工程教育部重点实验室开放研究基金项目(KLE-TJGE-B1101)

摘　　要：超软土固结特性在吹填土地基处理设计中至关重要,针对"浅层真空预压加固处理"前后的超软土开展室内分级加载固结试验,研究了不同状态、不同方向下超软土的固结特性以及固结系数随固结荷载的变化规律。试验结果表明,超软土在低应力水平下,固结系数维持在一个较低的水平;随着固结压力的增加,固结系数虽有所增加,但增量比逐渐减小;与正常沉积土不同,超软土的径向与竖向结构屈服应力的比值明显大于正常沉积土;当固结压力超过结构屈服应力时,超软土的径向固结系数与竖向固结系数相差不大,这一特点与正常沉积土有较大的差别。During the design of foundation treatment of dredger fill, it is a crucial problem to determine the consolidation properties of ultra soft soils. A series of consolidation tests with loading in increment are carried out on the ultra soft soils before and after surface-layer improvement by vacuum preloading. The consolidation characteristics and the coefficient of consolidation of ultra soft soils are investigated considering different states and directions. The test results show that the coefficient of consolidation remaines at a low level under lower stress levels. With the increasing consolidation pressure, the coefficient of consolidation has an increase, but the increment ratio decreases gradually. The ultra soft soil is different from the normal sedimentary ones, resulting in that the ratio of vertical to radial structural yield pressures of the ultra soft soils is significantly greater than that of the normally sedimentary soils. When the stress exceeds the structural yield pressure of the ultra soft soils, the radial coefficient of consolidation has no significant difference from the vertical one, and this characteristic has a large difference from that of the normally sedimentary soils.

关 键 词：超软土 结构屈服应力 固结系数 浅层加固 真空预压 

分 类 号：TU472[建筑科学—结构工程]