Abstract: Cracks on drainage gallery at dam block 19 were found recent years. The cause of cracks and its effects to dam safety was listed as a special itemin the second periodic daminspection. According to the results of FEM, cracks would not appear under normal conditions. It was found that the cracks appeared during construction by re- referring to construction records. The cause of cracks and its effects to damsafety were analyzed according to geological data and temperature monitoring data in construction.

摘要： 近年来, 发现了19 号坝段排水廊道的裂缝, 第二次大坝定期检查把裂缝成因及其影响列为专题研究项目之一。有限元结果表明, 正常情况下裂缝不可能出现。通过复查施工记录知裂缝出现在施工期, 根据地质资料和施工期温度监测资料, 分析探讨了裂缝成因及其对大坝安全的影响。