某地铁主体结构基坑开挖监测研究

ANALYSIS OF FOUNDATION PIT EXCAVATION OF MAIN STRUCTURE OF CITY STAR STATION OF METRO LINE

基坑监测作为基坑工程中的一项重要内容,对于基坑的稳定与安全性能有着极为重要的影响。以杭州地铁某主体结构基坑工程为背景,对基坑开挖过程中地表沉降和土体水平位移进行监测,研究地表沉降与时间的关系、地表沉降与空间的关系、深层水平位移等变化规律,结果表明地表沉降随时间逐渐增加,随空间呈现先增加再减小的凹槽型;地表最大沉降量出现在基坑长边中点附近;地下连续墙深层水平位移随开挖深度呈现“两头小,中间大”的趋势,深层最大水平位移随施工进度而增加。研究结果对类似基坑工程具有一定的指导意义。

As an important part of foundation pit engineering,the foundation pit monitoring has a very important im-pact on the stability and safety of foundation pit.Taking a foundation pit project of the main structure of Hangzhou Metro Line as the case,the surface settlement and the horizontal displacement of the soil mass during the excavation of the foundation pit are monitored,and the relationship between the surface settlement and time,the relationship be-tween the surface settlement and space,and the deep horizontal displacement are studied.The results show that the surface settlement gradually increases with time,and it increases first then decreases with space.The maximum sur-face settlement occurs near the midpoint of the long side of the foundation pit.The deep horizontal displacement of diaphragm wall shows the trend,which is small at both ends and large in the middle with the excavation depth,and the maximum deep horizontal displacement increases during the construction progress.The results may provide refer-ence for similar foundation pit projects.