贯通式衔接段周围敏感环境变形性状与工况匹配分析

Deformation and matched working condition analysis of sensitive environment around pass-through connection section

以近接基坑贯通式衔接段、先浅基坑后深基坑不同步施工时序为研究对象,以位移为监测参数,把贯通式衔接段周围敏感环境的位移监测数据与近接基坑开挖工况进行了匹配分析,结果表明:在衔接段周围,基坑开挖导致的环境效应影响距离在较大基坑开挖深度的2倍之内;拆除对撑于衔接段中埋入式支护桩顶的内支撑时,衔接段周围建筑物、道路、土体和冠梁等敏感环境的变形性状明显、同步,且位移值最大;设计时,要提高对撑于衔接段中埋入式支护桩顶的内支撑的轴向刚度;拆除该道内支撑时要加强监测,以便及时采取应急措施。

The study focuses on the adjacent excavations which are the pass-through connection section and the asynchronous construction sequence of shallow excavation followed by deep excavation.Based on the monitoring parameter of displacement,monitoring data of sensitive environment displacement around pass-through connection section have been matched and analyzed with excavation conditions.Results show that the environmental impact caused by excavation of the foundation pit around the connecting section is within twice the larger excavation depth.Deformations of building,road,soil and capping beam are obvious and synchronous and displacement values are maximal,removing the strut on the top of embedded support piles.It is necessary to increase the axial stiffness of the strut on the top of embedded support piles.When the strut is dismantled,it is necessary to strengthen monitoring in order to take emergency measures timely.