上海某商办楼基坑开挖施工监控量测分析

Monitoring,Measuring and Analysis of Foundation Pit Excavation and Construction of Commercial Office Building in Shanghai

以上海市某商办楼基坑项目为背景,针对基坑开挖过程中对周围地表沉降、地连墙、水位、围护结构的影响,进行开挖过程中全程监控量测并分析其规律.研究结果表明:周围地表沉降随基坑开挖深度不同沉降增加的速率不同,开挖基坑上半部分沉降较慢,开挖到中下层沉降速率加快;基坑开挖造成地连墙呈两头小,中间大的变形形态,且最大变形处位于基坑最底处;基坑开挖引起周围地下水位迅速下降,底板浇筑结束后,随着地下结构回筑,内衬墙封闭施工完成,坑外水位出现回升直到最后稳定;支撑轴力随着基坑开挖深度增加而增大,在基坑底板浇筑完成后支撑轴力逐渐稳定.

Taking the foundation pit project of a commercial office building in Shanghai as the background,aiming at the impact of foundation pit excavation on the surrounding ground settlement,ground diaphragm wall,water level and enclosure structure,the whole process of monitoring and measuring during the excavation process is carried out,and its rule is analyzed.The research results show that the surrounding ground settlement increases at different rates with different excavation depths of the foundation pit The settlement of the upper part of the excavated foundation pit is slower,and the settlement rate increases at the middle and lower layers of excavation.The excavation of the foundation pit causes the less displacement at the up and down of the ground diaphragm wall and larger displacement at the middle,and the largest deformation is located at the lowest bottom of the foundation pit The excavation of the foundation pit causes the surrounding groundwater level dropping rapidly.The water level outside the pit rises again and stabilizes until the end after the completion of closing construction of lining walL The supporting axial force increases with the increment of excavation depth of foundation pit The supporting axial force gradually stabilizes after the baseplate pouring of foundation pit.