合肥地铁3号线拔除废弃大直径钢管施工技术研究

Research on Hefei Metro Line 3 uprooted waste large-diameter steel pipe construction technology

合肥地铁3号线南延线云幸区间盾构在穿越交通繁忙的方兴大道交叉口期间,突遇埋置较深的大直径废弃燃气管线。采取挖探和钻探取芯相结合的方式,探明废弃管道与云幸区间左、右线隧道均冲突,影响盾构掘进。从工期、造价和施工风险等方面进行方案比选和专家论证,在有限空间内确定以“竖井+横通道+千斤顶”、拔除废弃钢管的方案,辅以管道周边减阻的施工工艺,成功快速拔除了废弃的大直径钢管,保证盾构施工顺利掘进,为今后类似条件下拔除大直径钢管提供借鉴。

During the passage of the heavily trafficked Fangxing Avenue intersection,the shield tunneling in the Yunxing section of the southern extension of Hefei Metro Line 3 suddenly encountered a deep buried large-diameter waste gas pipeline,and the combination of excavation and drilling coring was adopted to find out that the abandoned pipeline was in conflict with the left and right line tunnels in the Yunxing section,which affected the shield tunneling.From the aspects of construction period,cost and construction risk,the scheme comparison and expert demonstration were carried out,and the scheme of pulling out the waste steel pipe with"shaft+horizontal channel+jack"was determined in the limited space,supplemented by the construction technology of drag reduction around the pipeline,the waste large-diameter steel pipe was successfully and quickly pulled out,so as to ensure the smooth excavation of the shield construction,and provide reference for the uprooting of large-diameter steel pipes under similar conditions in the future.