盾构法输水隧洞二衬变形缝止水研究与应用

Research and Application of Waterproofing of Secondary Lining Deformation Joints in Shield Tunneling Water Conveyance Tunnels

城市中大型地下输水工程,盾构法施工二衬变形缝位置多采用“紫铜止水+闭孔泡沫板+聚氨酯嵌缝”结构,根据输水隧洞运行情况调查分析,变形缝内原施工材料随着使用年限的增加物理性能随之衰减,最终造成变形缝反水现象。文章通过多次试验探究,总结出了增加了微膨胀水泥浆及丙烯酸盐注浆的施工工艺,并在南水北调团九项目中得到了应用,可对类似的新建及检修项目提供参考借鉴。

In large-scale underground water conveyance projects in urban areas,the“brass water stopper+closed-cell foam board+polyurethane sealing”structure is commonly used for the location of deformation joints in the secondary lining during shield tunneling construction.Based on investigations and analysis of the operational conditions of water conveyance tunnels,it has been observed that the physical properties of the construction materials within the deformation joints deteriorate over time,eventually leading to water seepage through the joints.This paper presents the results of multiple experiments and proposes a construction technique that involves the use of micro-expansive cement slurry and acrylic acid salt grouting.This technique has been successfully applied in the South-to-North Water Diversion Project Phase IX,providing valuable references for similar new construction and maintenance projects.