摘要
以武汉长江Ⅰ级阶地中海国际大厦超深基坑工程为研究背景,使用静压薄壁取土器对该场地软土地层进行取样,并结合室内土工试验、利用数理统计原理获取软土地层的抗剪强度指标,并与采用岩芯管取样所得到的(qq)抗剪强度指标进行对比。同时运用Midas GTS三维有限元软件开展对中海国际大厦超深基坑工程的三维数值仿真分析,主要研究了超深基坑地下连续墙水平位移及地层土压力的变化规律,并与实测数据进行对比分析。研究发现:使用静压薄壁取土器取样对地层的扰动较岩芯管取样小,得到的土体抗剪强度指标更为可靠;选取cu抗剪强度指标,地下连续墙水平位移和地层土压力更接近实测数据,cq指标次之。建议对于一级重要性等级的基坑首选cu指标,对于二、三级重要性等级基坑可采用cq指标。
Taking the Zhonghai International Building ultra deep foundation pit in Wuhan Yangtze River I terrace as an object, the shear strength index of soft soil is obtained by using static pressure sampler, combining indoor soil test which include direct shear test(qq), consolidated quick shear test(cq), triaxial consolidated undrained test(cu) and triaxial unconsolidated undrained test(uu), and using the principle of mathematical statistics and comparing with qq shear strength index obtained by core tube. Meanwhile, a simulation analysis of Zhonghai International Building ultra deep foundation pit is carried out by 3D finite element software Midas GTS to study the variation of horizontal displacements of diaphragm wall and earth pressures of stratum mainly, and it is compared with measured data. It is found that using static pressure sampler for the perturbations of stratum is smaller than that of core tube. The shear strength index obtained by the static pressure sampler is more reliable. When selecting core tube shear strength index, the horizontal displacement of diaphragm wall and earth pressure of stratum are more closer to the measured data, cq index is followed.Proposal to select cu index for the first level excavation, and select cq index for the second and the third level excavations.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2014年第S2期306-312,318,共8页
Rock and Soil Mechanics
基金
武汉市建委科研项目(No.20123
文号武城建[2012]308)
关键词
深基坑
软土
抗剪强度指标
三维数值模拟
deep foundation pit
soft soil
shear strength index
3D numerical simulation
