顶管穿江隧道探孔封堵设计与施工

Design and construction of prospect hole plugging during the construction of river crossing tunnel based on pipe jacking method

在高水压水域顶管施工中遇到探孔、裂隙及其他流通性强的地质条件可能会对顶管泥水循环、进舱检查更换刀具等施工环节造成困难。以富春江顶管工程探孔及岩石层大裂隙封堵为例,介绍了复杂地质条件下大坡度纵向曲线顶管施工探孔封堵技术。分析了正常顶管施工中建立掘进泥浆循环需要满足的条件,对比正常段与有探孔存在而无法实施正常掘进泥浆循环下的各项施工参数,采用盾尾油脂在隧道外部止水、掌子面止水、泥浆性能指标控制、优化顶进参数等措施对探孔和大裂隙进行了成功封堵,为高水压顶管施工情况下的加压进仓刀具检查、更换创造了安全可靠的施工环境。该技术操作性强、成本低、实施效果好,为顶管穿越江河施工相关难题提供了借鉴和参考。

When pipe jacking operation is carried out in high-pressure water areas, high-flow geological conditions（e.g. prospect hole and crack） may bring difficulties to pipe jacking slurry circulation system, cutter check and replacement in the cabinet and so on. In this paper, the plugging of prospect holes and major cracks in Fuchunjiang pipe jacking engineering was taken as an example to introduce the prospect hole plugging technology used in the high-slope vertical curve pipe jacking operation under the complex geological conditions. The requirements for the establishment of driving slurry circulation in the normal operation of pipe jacking were analyzed. The parameters of normal sections were compared with those of the sections with prospect holes where driving slurry circulation cannot be conducted normally. Prospect holes and major cracks are plugged successfully by taking the following measures, such as sealing up outside the tunnel by using the shield tail grease, sealing up at the tunnel face, slurry performance index control and jacking parameter optimization, so as to provide safe and reliable operation environments for the check and replacement of pressurized inlet cutters during pipe jacking at high water pressure. This technology is advantageous with strong operability, low cost and good application effect. And it can be used as the reference for the solution of similar difficulties encountered during river crossing based on pipe jacking.