小湾拱坝施工期裂缝成因的再探讨  

Discussion on the causes of crack formation during construction of Xiaowan Arch Dams

作　　者：朱伯芳[1] 

机构地区：[1]中国水利水电科学研究院,北京100038

出　　处：《水利水电技术》2015年第4期1-5,共5页Water Resources and Hydropower Engineering

摘　　要：小湾拱坝裂缝主要由过大的温降幅度和温度梯度引起,其中二冷降温幅度过大和高度方向温度梯度过大是主要因素,上下游温度梯度过大是次要因素。如果仅仅取消上中下游分区冷却,由于二冷降温幅度过大和冷却区太小的问题没有解决,裂缝仍然难以避免。如果按照笔者在2005年提出的二冷前进行大范围中期冷却、冷却区高度（0.30-0.40）L、采用固定水流向或者同时开始冷却不同停水时间实现上下游3℃封拱温度差的方式进行通水冷却,裂缝是可以避免的。Xiaowan arch dam with the light of 294. 5 m was the highest arch dam in the world when it was completed in 2009.Some cracks had appeared in the period of construction. All the cracks had been treated properly before the grouting of transverse joints of the dam. The upstream water level had reached the maximum design value for several years. The wording of the dam is reasonable which indicates the dam is safe. The principal causes of cracking are the height ΔH of pipe cooling before grouting of joints was too small and the temperature differences were too big. The prevention of cracking is possible by means of rational temperature control.

关 键 词：水工结构 裂缝 成因 小湾拱坝 

分 类 号：TV642.4[水利工程—水利水电工程]