深基坑开挖对邻近既有地铁隧道及轨道结构的影响研究  

Influence of Deep Foundation Excavation on the Adjacent Existing Subway Tunnel and Track Structure

作　　者：宋晓凤 姚爱军[1] 张剑涛[2,3] 闫旭丽 郭彦非 

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124 [2]中国建筑科学研究院地基基础研究所,北京100013 [3]建研地基基础工程有限责任公司,北京100013

出　　处：《施工技术》2018年第5期122-127,共6页Construction Technology

基　　金：国家自然科学基金资助项目(51578023)

摘　　要：新建基坑工程施工过程中,在确保基坑自身安全的同时,也要控制由于基坑施工引起的土体位移,保证邻近地铁的安全和正常运营。以北京某深基坑工程为例,应用数值模拟方法研究了深基坑开挖施工对既有地铁区间隧道及轨道结构的影响,研究结果表明:受基坑与隧道位置关系影响,基坑开挖对邻近地铁隧道及轨道结构的影响主要以朝向基坑方向的水平位移为主,对轨道几何形位的影响较小;隧道及轨道结构的水平及竖向位移、轨道的轨距及水平变化沿隧道轴线方向呈"一"字形均匀分布,随着施工步序变化的时程曲线呈勺状分布;当基坑侧壁与盾构隧道水平净距l>2h(h为基坑开挖深度)时,基坑开挖对邻近地铁隧道及轨道结构的影响较小,可以2h为界限将基坑施工邻域分为强影响区和弱影响区;基坑支护结构采用双排桩时,较单排桩而言可明显降低基坑开挖对地铁隧道及轨道结构的影响,尤其可抑制隧道结构水平位移的发展。In the construction of new foundation excavation which locates in the area adjacent to the existing subway,it is necessary to control the movement of nearby strata due to the excavation of foundation to ensure that adjacent subways are safe and operate normally while ensuring the security of the foundation excavation itself. In this paper,a deep foundation excavation in Beijing was used as the engineering example and a numerical simulation method was used to study the influence on the interval shield tunnel and track structure of adjacent existing subway due to foundation excavation. The results prove that： affected by the location between foundation excavation and tunnel,the additional deformation of adjacent subway shield tunnel and track structure caused by the foundation excavation is mainly horizontal displacement and the track structure shows small effect. In the direction of the shield tunnel axis,the horizontal and vertical displacement of subway shield tunnel and railway track structure are distributed uniformly and the time history curves are distributed as spoon type. When the horizontal clearance between shield tunnel and the edge of deep foundation excavation is more than 2 h（ h： depth of deep excavation）,the additional deformation of adjacent subway shield tunnel and track structure caused by the foundation excavation are weaker. Taking 2 h as the boundary,the building construction area can be divided into strong influence area and weak influence area. As a kind of retaining structures of deep excavations,the double row piles can dramatically lower the influence of deep foundation excavation onshield tunnel and track structure when compared with the single row piles,especially can restrain the horizontal displacement of the shield tunnel.

关 键 词：深基坑 地铁 轨道结构 轨道几何形位 数值模拟 

分 类 号：TU753[建筑科学—建筑技术科学]