三峡纵向碾压混凝土围堰温控设计

Temperature Control Design for First-stage Longitudinal RCC Cofferdam

三峡一期纵向碾压混凝土围堰长1191．47m，混凝土工程量150．6万m3，其中碾压混凝土130．3万m3。根据围堰运用条件、结构特点、防裂要求、碾压混凝土性能试验资料和1997年大江截流控制性进度，确定围堰碾压混凝土的温度控制标准和温控措施。为满足温控防裂和层面结合要求，夏季6～9月份永久建筑物等重要部位不浇碾压混凝土。采取的主要温控措施有：保证混凝土抗裂能力；合理安排施工程序；控制坝体最高温度；坝身段采取中期通水降低内外温差；加强表面保护；合理分缝分块，对防裂要求高且块体尺寸大的上纵堰内段和坝身段设置诱导缝。

The longitudinal cofferdam has a lengh of 1191. 47 m and a concrete volume of 1, 506, 000 m3, of which 1, 303, 000 m3 is of the roller compacted concrete. The standards and measures of temperature control were based on the operation conditions of the cofferdam,the structure features,the requirements for anticracking,the data from RCC property experiments and the key schedule of the river closure in 1997.