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。
The analysis on monitoring data of shield launching wells for the Nanjing Subway tunnel acrossing Yangtze River, such as surface settlement, deep soil displacement, axial force of struts, underground water level and wall top horizontal displacement and settlement, are analyzed, especially the changes during the piping. The main results are as follows： the maximum surface settlement point is 0.5 times depth of the foundation excavation away from the edge of it. The influence of excavation is 2 times depth of the foundation. The struts bearing force is closely related to excavation, temperature, rainfall and water level. When excavation depth is 0.75 times of the depth of foundation excavation, settlement changes a lot. At this time, the top ring beam, the cross section and stiffness of support are very important to control the deformation. Appropriately increasing stiffness or section can effectively reduce the deformation and surface subsidence. The underground water level reflects the watertight effect of the retaining structures, which affected by the conditions, rainfall and water level of the Yangtze River, with some lag. Construction units can preliminary judge the sand source through the monitoring data of the surface settlement.
出处
《施工技术》
CAS
北大核心
2014年第7期98-102,121,共6页
Construction Technology
基金
海南大学科研启动基金资助项目(kyqd1241)
关键词
隧道工程
地铁
中间风井
位移
监测
tunnels
subways
middle wind well
displacement
monitoring
