龙滩碾压混凝土大坝设计及施工实践

龙滩水电站大坝为目前世界上最高的碾压混凝土大坝,坝高216.5 m,按常规重力坝进行坝基和坝体结构设计.通过现场试验,确定了设计采用的碾压混凝土层面抗剪断强度参数值;大坝底部采用以变态钢筋混凝土与二级配碾压混凝土组合为主,以水泥基渗透结晶材料涂层及黏土铺盖为辅的防渗设计,大坝上部采用变态混凝土与二级配碾压混凝土组合防渗设计.通过优化混凝土配合比设计、选择合理的施工方案、精心的仓面组织设计以及温控措施的落实等,龙滩大坝实现了高气温条件下全年连续、快速、优质施工,现在大坝基本完成,达到了设计目的.

Design and construction of RCC dam for Longtan Hydropower Project

Longtan Hydropower Project has the highest RCC dam of the world with a height of 216.5m.The structure of dam foundation and body were designed as conventional gravity dam.The RCC bedding shear strength parameter as design basis was determined by site tests.The impervious design for the lower part of main dam mainly incorporate distorted reinforced concrete and II grading RCC with cement permeable crystal coating and clay as auxiliary measures.The seepage prevention measure for the upper part of main dam is the combination of distorted concrete and II grading RCC.By optimizing the mix proportion,selecting proper construction scheme,conducting aboratively workface organization design and implementing temperature control measures,the main dam was continuously and rapidly constructed with good quality over the whole year,including the days with high temperature.The construction of main dam is nearly completed up to design targets.