98
D0I:10.7672/sgjs2014070098
施工技术
CONSTRUCTIONTECHNOLOGY
2014年4月上第43卷第7期
南京地铁过江隧道中间风井施工监测分析
沈鑫国"，胡俊？，曹东辉3
（1.华东电力设计院，上海200001；2.海南大学土木建筑工程学院，海南
海口570228；
3.杭州市建筑设计研究院有限公司，浙江杭州310000）
【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、降南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、支撑的裁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，可通过监测地表沉况降初步判断涌砂的来源。【关键词】隧道工程；地恢；中间风井；位移；监测
【中图分类号】TU443
【文献标识码】A
[文章编号】1002-8498（2014)07-0098-05
MonitoringAnalysisof ShieldLaunching Wells
inNanjingSubwayTunnelAcrossingYangtzeRiver
Shen Xinguo', Hu Jun', Cao Donghui
(1. East China Electric Power Design Institute, Shanghai 200001,China;
2. College of Cisil Engineering and Arehitecture of Hainan University, Haikou, Hainan 570228, China; 3. Hangzhou Architectural Design & Research Institute Co. ,Ld., Hangzhou, Zhejiang 310000, China)
Abstract: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 O.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 O.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.
Key words;tunnels; subways; middle wind well; displacement; monitoring
.
引言
南京轨道交通建设已经迈入高速发展阶段，现
已有1,2号线投人运营，在建的有3，4，10号线，正在勘察的有4,6，11,12号线。大量的地铁建设伴随而来的是大量深基坑工程，特别是过江隧道的深基
*海南大学科研启动基金资助项目（kyqd1241）
【作者介】沈盒国，硕士，E-mail；shenxg2743@ecepdi.com
【收稿日期】2013-03-29 万方数据
坑，常常处于深厚含水层，受承压水影响很大，极易导致围护结构变形过大，严重时出现涌砂、管水等事故。前人对基坑开挖的研究已有很多[1-9]，主要成果如下：墙体水平位移与基坑平面尺寸密切相关，也是评价围护结构安全状况的重要指标135,7.9];支撑轴力与开挖方式、速度、工况等有着密切关系（3,5)；地表沉降有抛物线分布或三角分布，且前期沉降速率大，变形快，后期沉降速率小，变形