丹江口大坝加高溢流表孔水下封堵施工技术

Underwater Plugging Construction Technique of Surface Spillways in the Danjiangkou Dam Heightening Project

确保混凝土浇筑施工的干场作业条件,是丹江口大坝溢流堰面加高混凝土浇筑项目的关键环节。通过方案比较,选择空腔混凝土叠梁浇筑水下混凝土和钢叠梁闸门相结合的方案进行水下封堵施工。现场施工过程中克服现有工程技术条件,相继解决了混凝土叠梁安装定位、浇筑前止浆、水下混凝土浇筑、水下新增钢叠梁闸门底坎及后期渗漏处理等问题,并首次在水下进行闸门底坎埋件安装、调平,同时采用新型水下不分散、自流平的聚合物树脂混凝土作为底坎埋件的二期混凝土,形成完整的闸门底坎止水结构。

Dry land is a critical working condition for concrete pouring of the overflow dam heightening project of the Danjiangk- ou dam. Different schemes were compared and the combination method of cavity concrete stop logs with underwater concrete pouring and steel stop log gates was selected. During the construction, several problems were solved such as the installation po- sitioning of concrete stop logs, grouting stopping before pouring, underwater concrete pouring, added underwater sills of steel stop log gates, and later leakage treatment. Moreover, the gate sills were installed and leveled under water for the first time and the new type of anti-washout and self-compacted polymer resin concrete was used as the secondary concrete for sill embedded parts to form a complete sill sealing structure.