Abstract: Drainage channel of dam transverse joint is designed for facilitating the waterstop inspection and processing, but in the case of massive leakage from drainage channels, materials and procedure of traditional chemical grouting, such as the use of water-soluble elastic polyurethane LW in grouting and plugging, can easily cause the feeding pipe burst due to its rapid reaction with water. In this paper, an innovated chemical grouting process based on hydrostatic displacement mode is proposed, which can effectively control the pressure and flow at the inlet and outlet. The grouting process is carried out in the order of isolating agent, guiding fluid and finally the main material——mixture of LW and HW, which can effectively avoid the premature contact of LW and water, and achieve good grouting result.

Key words: dam, drainage channel, chemical grouting, new technology

摘要： 大坝横缝排水槽的设计为止水检查及处理提供了便利，但在排水槽大量漏水情况下，传统化学灌浆材料及工艺，例如采用水溶性弹性聚氨酯LW灌浆封堵，由于LW与水迅速反应，极易造成进浆管爆管。笔者提出一种创新的化灌工艺，以静水置换方式，有效控制进浆口和回浆口的压力与流量。首先灌注隔离剂，再灌注先导液，最后灌注主材LW与HW混合液，有效避免了LW与水过早接触反应，灌浆效果良好，具有推广价值。

关键词: 大坝, 排水槽, 化学灌浆, 新工艺