2010年11月第39卷第11期
施工技术
CONSTRUCTION TECHNOLOGY
武汉地铁2号线盾构施工对地表沉降影响分析
冯虎，张文成2，孙士玲2
(1.郑州大学土木工程学院，河南郑州450002；2.上海同是工程科技有限公司，上海200092)）
【摘要】对武汉地铁2号线盾构据进施工过程中地表沉降监测数据统计，并根据Peck理论进行拟合对比分析，得到盾构施工引起纵横断面地表沉降的特点：纵向上，盾构机切口前30m以内和后50m以内为影响区域，其中又以切口后50m为显著影响区，盾构通过该区域产生的沉降占总沉降量的80%－90%，盾构对某断面上影响范围在潜盾构中心轴线向左右两侧延伸10-18m；对武汉粉质黏土夹粉土粉砂层，盾构掘进引起的地表沉降数据累计变化控制
指标宜为-40mm，盾构机切口通过监测断面6-20m范围内单次平均变化速率控制值宜为-15mm/d。【关键词】地铁；盾构施工；地表沉降；Peck公式
【中图分类号】U455.43
【文献标识码］A
［文章编号】1002-8498(2010)11-0075-04
Analvsis on Influence of Shield Construction to Ground-surface
Settlement in Wuhan Subway Line2 Feng Hu', Zhang Wencheng’, Sun Shiling
(1. School of Ciril Engineering, Zhengzhou Unirersity, Zhengzhou, He' nan 450002, China ; 2. Shanghai Tongshi Engineering Technology Co, , Ld. , Shanghai 200092, China)
Abstract : The ground-surface settlement caused by shield construction is monitored in Wuhan Subway Line 2. Meanwhile the ground-surface settlement is simulated with Peck formula. Comparing the monitored and simulated settlement, some conclusions about the ground-surface settlement characteristics are obtained. In vertical cross-section, the impact region is 30m before shield incision and 50m after shield incision, and the later region is significantly impact region. The settlement amount caused by shield passing through is 80% ~ 90% of the total settlement. Shield impact region of a cross-section along the central axis of shield extends to the right and left sides within 10 ~ 18m. For the silty clay silt and silty sand layers in Wuhan, control index of cumulative ground-surface settlement caused by shield construction might be 4Omm, and the control index about the average single settlement changing might
be 15mm/d, within 6 ~ 20m of shield incision through the monitoring cross-section. Key words : subway; shield construction; ground-surface settlement; Peck formula
武汉汉口地区工程地质、水文地质非常复杂，既有深厚软土，又有粉土、粉砂、互层及承压水的影响。在此种地质条件下进行地铁盾构施工，对变形控制有更加严格的要求。本文结合Peck理论对武汉地区盾构施工引起地表沉降变化情况进行初步分析，以期得到适用于武汉特殊地质情况下盾构施工对地表扰动的沉
降控制标准。工程概况
1
武汉地铁2号线一期工程某区间位于汉口，线路周边各种建筑物密集、地下管线密布，场地地貌为长江北岸冲积I级阶地。盾构起论里程为：CK4右+ 743.906~CK5右+758.399，右线长1014.493m，左线
75
长1017.576m，总长2032.069m。区间设一个联络通道，与泵房合建，里程为：CK5（右）+220.000；设有2 个平面曲线，最小曲线半径700m，线间距12~15m。线路最大纵坡坡度14%，最小坡度2%，区间结构平均覆土厚度约11m。
该区间隧道为外径6m、内径5.4m、管片拼装衬砌的单洞圆形隧道，管片环宽1.5m，管片采用C50，P12 混凝土。
[收稿日期】2010-01-18
【作者简介］冯虎，郑州大学土木工程学院讲师，郑州市文化路 97 号450002, 电话：13918295448,E-mail:honghoogeo@ 163. con