南京地铁过江隧道中间风井施工监测分析

发布时间：2018-11-27 21:00

【摘要】：对南京地铁过江隧道中间风井开挖时的地表沉降、深层土体位移、支撑轴力、地下水位及墙顶水平位移与沉降的监测结果进行分析,并着重对比研究2次管涌期间各监测项目的变化情况,监测结果表明:地表沉降最大值位于距离基坑边0.5倍基坑深度处,开挖对周边影响范围为2倍基坑深度;支撑轴力与开挖工况、温度、降雨和水位有着密切关系;当基坑开挖到0.75倍基坑深度时,沉降明显变大,此时此处冠梁、支撑的截面和刚度对控制基坑变形至关重要,适当增加刚度或截面可以有效减小基坑变形及地表沉降。地下水位反映围护结构止水效果,受工况、降雨和长江水位等影响,有一定滞后性,可通过监测地表沉降初步判断涌砂的来源。
[Abstract]:The monitoring results of ground surface settlement, deep soil displacement, supporting axial force, underground water level and horizontal displacement and settlement of wall top during excavation of the middle air shaft of Nanjing Metro Tunnel are analyzed. The monitoring results show that the maximum ground subsidence is 0.5 times deep from the edge of the foundation pit and the influence range of the excavation is 2 times the depth of the foundation pit. The supporting axial force is closely related to the excavation condition, temperature, rainfall and water level. When the foundation pit is excavated to 0.75 times the depth of the foundation pit, the settlement becomes larger obviously. In this case, the section and stiffness of the crown beam are very important to control the foundation pit deformation, and the proper increase of the stiffness or section can effectively reduce the foundation pit deformation and surface settlement. The groundwater level reflects the sealing effect of the retaining structure and is affected by the working conditions, rainfall and the water level of the Yangtze River, and has a certain lag property. The source of sand surge can be preliminarily judged by monitoring the surface subsidence.
【作者单位】：华东电力设计院;海南大学土木建筑工程学院;杭州市建筑设计研究院有限公司;
【基金】：海南大学科研启动基金资助项目(kyqd1241)
【分类号】：U456.3;U459.5

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