杭州某地铁车站深基坑开挖施工监测分析

Construction monitoring analysis of deep foundation pit excavation of a metro station in Hangzhou

以杭州地铁某车站深基坑开挖为工程背景,对该基坑开挖引起的支撑轴力、地表沉降、建筑物沉降以及周边地下管线沉降实测数据进行分析.研究结果表明:基坑开挖初期提高支撑轴力监测频率并加快支撑的布设,是保证基坑安全施工的重要手段;后续支撑的架设会使第一道支撑轴力产生拉力,要防止第一道支撑与围护结构脱开;地表沉降最大点与基坑边有一定距离,沉降曲线多呈盆形;基坑开挖会使邻近建筑物产生不均匀沉降;周边地下管线与地表的沉降大小和测点与基坑的相对位置有关,标准段附近沉降大于端头井段,标准段中部沉降最大,平行于基坑边的管线产生不均匀沉降.

Based on the deep foundation pit excavation of a metro station in Hangzhou, the monitoring data of bracings; axial force and ground settlement, building settlement, surrounding underground pipeline set- tlement caused by foundation pit excavation have been analyzed. The results show that the increasing fre- quency of axial force monitoring and speeding up the layout of bracings in the early days of excavation is a good way to ensure construction safety. The follow-up bracings will make the axial force of the first brac- ing be tensile force; and it＇s necessary to prevent the first bracing from getting out of the exterior protec- ted construction. There is a distance between the maximum surface settlement point and the foundation pit, and most settlement curves are basin shaped. The adjacent building shows the uneven settlement be- cause of the excavation. Surrounding underground pipeline settlement and ground settlement are related to the relative position of monitoring site and foundation pit. When the settlement near the standard segment is larger than that near the end well segment; the maximum settlement point is near the middle of the standard section segment. The pipelines parallel to the edge of the foundation pit show the uneven settlement.