市政管道基坑施工对既有地铁结构的影响研究

Study on the influence of municipal pipeline project on the structure of existing metro

地铁沿线开展工程建设必然对地铁结构和运营带来安全隐患。市政通道基坑上跨地铁将引起地铁结构上浮或结构应力变化,进而导致结构破坏或影响运营。本文通过多种手段,准确、合理的评价雨水管道对暗挖结构的影响,为合理采取措施奠定基础。1)通过工程相互关系,提出雨水管道建设对地铁的影响主要应研究三个问题:通道开挖卸载引起的地层回弹、通道开挖引起暗挖隧道的上浮变形、侧向变形。2)通过地铁结构现状分析和监测成果分析,提出了有针对性的结构控制标准。3)通过数值计算分析认为,基坑开挖引起的隧道的最大上浮为:2.4 mm,侧向变形为:0.12mm;对于车站工程,基坑开挖引起的最大竖向变形为:2.1 mm,侧向变形为0.23 mm;通过工程实例对比分析认为,预测管道工程基坑开挖引起的地铁车站、风亭和隧道结构变形约2~3mm,引起A3出入口变形约5-6mm。

The construction of projects along the line of the subway will inevitably bring safety risks to the subway structure and operation. The metro crossing over the municipal passageway will cause the subway structure to float or change the structural stress, which will lead to the structural damage or affect the operation. In this paper, the influence of storm water pipe on underground excavation structure is accurately and reasonably evaluated by various means, which lays a foundation for taking reasonable measures. 1) based on the relationship between projects, it is proposed that the influence of rainwater pipeline construction on the subway should be mainly studied in three aspects: the stratum rebound caused by the excavation and unloading of the tunnel, the upward deformation caused by the excavation of the tunnel, and the lateral deformation. 2) by analyzing the status quo of subway structure and monitoring results, the targeted structure control standards are proposed. 3) according to numerical calculation and analysis, the maximum uplift of the tunnel caused by foundation pit excavation is: 2.4 mm, and the lateral deformation is: 0.12 mm;For station engineering, the maximum vertical deformation caused by foundation pit excavation is: 2.1 mm, and the lateral deformation is 0.23 mm;Through the comparative analysis of engineering examples, it is concluded that the structural deformation of subway station, wind pavilion and tunnel caused by foundation pit excavation of pipeline engineering is about 2 ~ 3 mm, and the deformation of A3 entrance is about 5-6 mm. Comprehensive analysis shows that the influence of tunnel construction on metro engineering is controllable.