摘 要

   随着我国经济社会的不断发展以及城市化进程的逐步推进，我国各主要城市相继开展了城市轨道交通的建设。以地铁为代表的城市轨道交通建设为推进我国城市化建设进程、促进国家经济社会的发展起到了重要的作用。然而，由于地铁建设的高风险性，历史数据表明在地铁建设的过程中由于各方面的原因时常会造成一定程度的安全事故。地铁建设过程中由于隧道施工引起的地表沉降是影响地铁施工安全的重要因素之一，它不仅关系到地铁隧道自身的安全性，也对地铁沿线地表建（构）筑物的安全带来了潜在威胁。密切关注地铁建设过程中地表沉降变化，科学合理的分析和预测地表沉降将为地铁隧道施工提供一定的安全预警作用。

   本文在查阅大量文献并对实际工程数据分析研究的基础上，首先对平行双线隧道施工引起的地表沉降的形成机理进行了归纳和总结，然后对平行双线地铁隧道施工引起的地表沉降的特点和规律进行了阐述。随后，文章以武汉地铁 2 号线 1 期工程 25 标为例，通过对监测断面数据的分析，对平行双线地铁隧道施工引起的地表沉降的影响因素进行了探讨，并对施工引起的地表沉降的影响因素—隧道上覆土质、隧道埋深和施工工艺作了因素分析。最后，文章仍然以武汉地铁 2 号线 1 期工程 25 标为例，通过监测断面的筛选，地表沉降数据的分析，基于 peck 公式并对小间距叠加法进行相关修正的基础之上对若干断面的地表沉降进行了预测。

关键词：地铁隧道   矿山法施工   地表沉降   经验法   Peck 公式

Abstract

   With the continuous economic and social development and the gradual promotion ofUrbanization process, China's major cities have undertaken the construction of urban railtransit.  Urban  rail  transit  represented  by  metro  has  played  a  veryimportant  role  inpromoting  our  national  urbanization  process  and  accelerating  our  country’s  economicand social development. However, as the highrisk of metro construction, historical datashow that in the process of metro construction,various security incidents often happen.In  the  process  of  metro  construction,  ground  surface  settlement  due  to the  metroconstruction is a key factor which influences the metro construction safety. It is not onlyrelated  to  the  subway  tunnel  own  security,  but  also  a  potential  security  threat  to  thesurface structures and buildings along the subway line. So Paying a close attention to thesurface settlement changes in the subway construction process, analyzing and predictingthe ground surface settlement scientifically and reasonably will provide certain referencefor the security of the subway construction and also provide necessary safety guarantee for structures and buildings along the subway line.

   In this paper, on the basis of consulting related documental materials and analyzingthe actual engineering data, firstly summarizes the surface settlement mechanism causedby  parallel  twin  tunnels  construction  and  introduces  the  rules ofground  surfacesettlement caused by parallel twin tunnels. Then, taking 25thsection1 stage project ofWuhan metro line 2 as an example, influence factors of surface subsidence caused by theparallel double tunnel construction were discussed and factor analysis are made. Finally, the article still takes 25thsection1 stage project of Wuhan metro line 2 as an example, by screening the monitoring crosssection and analyzing the crosssection data, based onthe  Peck  formula  and  making  a  small  correction  on  the  small  spacing  superposition method, ground surface settlement of some sections are predicted.

   Key words：Metro Tunnel     Mining Method    Ground Surface Settlement      Experience Method    Peck Formula