建筑基坑支护工程施工阶段对地铁影响的预评估

Pre-Assessment of the Impact of the Construction Stage of the Building Foundation Pit Support Project on the Subway

为了确保基坑支护工程施工过程中地铁的安全,结合坪山沙湖社区“整村统筹”土地整备项目留用地12号地块项目的工程条件、基坑工程设计及施工方案,采用数值分析方法对基坑支护、开挖过程等工况进行模拟,评估基坑开挖各个工况对轨道交通设施的影响。结果表明:(1)拟建项目基坑与地铁隧道最近距离为8.4 m时,地铁隧道最大侧移为2 mm,在地铁允许变形值范围内;(2)地铁埋深28.1 m,基坑开挖深度为14.1 m,地下水变化对地铁影响较小,地铁沉降最大值为1.7 mm,满足规范对变形值的要求;(3)提出的基坑支护方案满足现行地铁安全变形控制要求。

Based on the engineering conditions,foundation pit engineering design and construction plan of the No.12 plot of the reserved land for the“whole village overall planning”land preparation project,the numerical analysis method is used to simulate the foundation pit support,excavation process and other working conditions,and the foundation pit excavation is evaluated.The impact of various working conditions on rail transit facilities.The results show that:(1)When the closest distance between the foundation pit and the subway tunnel of the proposed project is 8.4 m,the maximum lateral displacement of the subway tunnel is 2 mm,which is within the allowable deformation value of the subway;(2)The buried depth of the subway is 28.1 m,and the excavation depth of the foundation pit is 14.1 m,the change of groundwater has little effect on the subway,and the maximum subsidence of the subway is 1.7 mm,which meets the requirements of the specification for the deformation value;(3)The proposed foundation pit support scheme meets the current subway safety deformation control requirements.