龙滩大坝混凝土供料线的优化设计及关键技术

Optimal Design and Key Technology of Concrete Supply Line for Longtan Hydropower Project

龙滩水电站大坝为碾压混凝土重力坝,大坝混凝土总量约736万m3,其中碾压混凝土约480万m3。龙滩大坝混凝土运输供料线系统由拌和楼出料皮带机和系统连接皮带机、3条高速皮带机供料线、3条负压溜槽和2台塔式布料机组成。混凝土运输供料线是大坝混凝土浇筑的关键设备,每条供料线的平均输送能力为330 m3/h,输送能力为水电工程之最。如何保证混凝土在运输过程中防止骨料分离、漏浆,降低坍落度损失,减少温度回升,保证入仓强度是混凝土供料线系统布置设计的重点。文章主要介绍了混凝土运输供料线系统结合龙滩工程现场条件进行布置,优化设计方案、关键技术以及关键技术问题的解决措施等。经优化设计的供料线系统投入使用后,运行情况良好,总体来说是成功的,为龙滩大坝高强度的混凝土浇筑作了重要贡献。

The dam for Longtan Hydropower Project is a RCC gravity dam. The total amount of concrete used for the clam is 7,360,000m^3, among which there is 4,800,000m^3 of RCC. The concrete delivery system for the dam is composed of mixer feeding conveyer, system connecting conveyer, 3 high-speed belt conveyer lines, 3 vacuum-chutes and 2 sets of tower crane placers. As the key component of concrete pouring for the dam, the concrete delivery system boasts the largest delivery capacity in hydropower projects with an average delivery capacity of 300m^3/h per line. The design of concrete delivery system highlights the prevention of mortar segregation and loss during concrete delivery, the reduction of slump loss and temperature re-increase, as well as the assurance of placement rate. This paper, by taking into account the site conditions of Longtan Hydropower Project, deals briefly with the layout, the optimal design and key technology of the concrete delivery system as well as the solutions to major technical problems. The optimized system has been working well ever since it was put into operation, which has contributed a lot to the intense concrete pouring of the clam for Longtan Hydropower Project.