特高拱坝表孔溢流面混凝土翻模工艺优化

Optimization of concrete turnover formwork technique for surface outlet overflow surface construction of super-high arch dam

锦屏一级水电站大坝溢流面混凝土施工在设计阶段拟采用常规工艺,实际施工过程中发现可能无法满足度汛对工期的要求。经过技术分析,并借鉴国内成功实施的大坝溢流面混凝土施工经验,提出了溢流面混凝土与大坝混凝土一次浇筑、溢流面层采用翻模工艺、支撑大梁采用悬臂支模的优化方案。工程实践表明,新的工艺方案保证了溢流面混凝土的结合质量,且节约工期5~7个月,相关经验可供类拟工程借鉴。

At design stage,conventional technique was to be adopted for the construction of overflow surface concrete in Jinping Ⅰ Hydropower Station. But in the actual construction,it was found that conventional technique could not meet the time limit requirements of flood prevention. Drawing on technical analysis and lessons from the successful experience of dam overflow surface concrete construction,a series of optimization measures are proposed,including one- time pouring for overflow surface concrete and dam body concrete,new turnover formwork technique used in overflow surface concrete construction,cantilevered formwork used in supporting girder. The engineering practices show that the new construction techniques not only can effectively guarantee the bonding quality of the overflow surface concrete,but also can shorten the construction duration by 5 to 7 months.