大跨地铁风道导洞开挖的地表沉降分布规律研究  

Distribution of Ground Subsidence Caused by Large-Span Subway Duct Excavation

作　　者：胡少斌[1] 张立平[1] 边宁宁[1] 李晓文[1] 李增光[2] 

机构地区：[1]北京城乡建设集团有限责任公司,北京100079 [2]北京交通大学土木建筑工程学院,北京100044

出　　处：《铁道标准设计》2017年第2期105-109,共5页Railway Standard Design

基　　金：北京城乡建设集团有限责任公司科技研究开发计划项目(2015-01)

摘　　要：北京地铁8号线大红门桥站-和义站区间附属风道为跨度16.2 m的单跨结构,采用暗挖洞桩法(PBA工法)施工。为有效控制导洞开挖引起的地表沉降,必须合理安排导洞施工顺序。基于三维数值模拟方法对不同的导洞开挖方案地表沉降分布规律进行研究,并与地表沉降监测结果进行比较分析。结果表明:不同的导洞开挖顺序的地表沉降发展路径差别显著,但最终的沉降值基本一致;随着导洞的开挖,地表沉降槽宽度增加并不明显,但是由于导洞开挖的群洞效应,地表沉降速度发展较快。因此在后续的拱部开挖支护中,必须通过调整支护措施和开挖方案来严格控制地层沉降。The subway duct of Dahongmenqiao-Heyi interval tunnel of Beijing metro line 8 is a single span tunnel with 16. 2 m span. The subway duct is constructed with PBA method （ Pile-Beam-Arc construction method）. The construction sequence of pilot tunnels should be reasonably determined to ensure that the ground subsidence is effectively controlled. The distribution of ground subsidence caused by different excavation methods for the pilot tunnel is studied with numerical simulation. The calculation results are compared with the monitoring results,which show that the pilot tunnel excavation sequence has significant impact on the development of the surface subsidence, but the final surface subsidence shows no obvious difference. With the excavation of pilot tunnels,there is no significant increase in the width of subsidence zone, but the ground subsidence velocity increases rapidly due to the group effect generated by the excavation of the pilot tunnels. It is concluded that support measures and excavation scheme should be adjusted to control ground subsidence in the following progresses of arch excavation and support.

关 键 词：地铁大跨风道 PBA工法 导洞 开挖顺序 地表沉降 

分 类 号：U231.3[交通运输工程—道路与铁道工程]