地铁风亭深基坑开挖拆墙对已建车站的影响

Impact of Subway Wind Pavilion Deep Foundation Pit Excavation and Wall Demolition on Existing Stations

  • 摘要:
    目的 对于风亭等车站大型附属结构施工,须同时进行深基坑开挖以及拆除与既有车站衔接处的大面积墙体,应深入研究该类施工对既有车站的影响。
    方法 依托苏州地铁8号线某车站施工工程,采用了有限元模拟与现场监测的方法,分析了风亭施工时车站主体结构的受力变形规律,识别出施工重点影响区域,得出拆墙面积与影响区构件受力变形的关系。
    结果及结论 风亭施工时基坑开挖与大面积拆墙使得车站结构受力急剧变化,产生变形,其影响范围集中于洞周区域。风亭深基坑开挖对于车站结构整体变形规律起着主导作用。拆墙施工对于风亭下方侧墙侧移及邻近楼板竖向位移的影响,随累计拆墙面积增加分别近似呈指数与线性正相关关系,而较少受到远端风亭拆墙施工的影响。拆墙施工导致风亭洞口处的边柱轴压增大,且各柱间荷载分配不均,呈现中间大、两端小的对称分布规律。拆墙施工引起的边柱轴力增加值与累计拆墙面积近似呈线性正相关关系。

     

    Abstract:
    Objective For the construction of large ancillary structures such as wind pavilions for subway stations, deep foundation pit excavation simultaneously with demolition of large wall sections connecting to the existing station is required, necessitating an in-depth research about the impact of such construction on the existing stations.
    Method Based on the construction project of a station on Suzhou Metro Line 8, the deformation patterns of the main station structure under stress during wind pavilion construction are analyzed with finite element simulation and onsite monitoring methods. Key construction-impacted areas are identified, and the relationship between the wall demolition area and the deformation of structural components under stress in the impacted area is determined.
    Result & Conclusion  During wind pavilion construction, the deep foundation pit excavation and large wall demolition result in sharp changes in the stress on the station structure such as deformation, with the impact concentrated around the vicinity of the opening. The deep foundation pit excavation for the wind pavilion plays a dominant role in the overall deformation pattern of the station structure. The influence of wall demolition construction on the lateral displacement of the side walls below the wind pavilion, and the vertical displacement of adjacent floor slabs shows an approximately exponential and linear positive correlation with the cumulative demolition area, respectively, while the impact of wall demolition in the wind pavilion far-end is minor. Wall demolition construction increases the axial compressive force in the edge columns at the wind pavilion opening, with an uneven load distribution among the columns, exhibiting a symmetric distribution pattern with larger loads in the middle and smaller loads at both ends. The increase in axial force of the edge columns due to wall demolition shows an approximately linear positive correlation with the cumulative demolition area.

     

/

返回文章
返回