为了改变冷冻法止水更换盾构盾尾刷施工成本高、工期长的行业现状，解决浅覆土、高水压、强透水地层更换盾构尾刷止水难度大、渗漏风险高的技术难题，南京纬三路过江通道N线工程采用提前预制特殊管片，增加径向预留注浆孔，不断优化注浆配比、注浆参数和注浆工艺，进行有效注浆的方法，并配以相应的辅助措施，最终达到更换盾尾刷时的止水要求，顺利完成了复杂地质条件下的超大直径泥水盾构盾尾刷更换施工，比采用冷冻法加固止水大大节约了工期和成本，具有较高的社会效益和经济效益。

Freezing method is always used in shield tunneling to facilitate the replacement of the tail brushes. However, the freezing method has such disadvantages as high cost and long construction duration. During the boring of Weisanlu Yangtze River Crossing Tunnel in Nanjing, the tail brushes have to be replaced under high water pressure and shallow highlypermeable cover. Therefore, special segments with embedded radial grouting holes are precast in advance, the grout mixing proportion, the grouting parameters and the grouting process are optimized, and effective grouting is made. In the end, the tail brushes have been replaced successfully. Compared to the conventional freezing method, the grouting method adopted in the project has lower construction cost and shorter construction duration. The practice can provide reference for similar projects in the future.