Abstract: The Sanbanxi reservoir had been in operation with low water level for 18 months. As impounding to high water level, increase of seepage was found. By underwater inspection, the result showed that the joints of 12 face slabs were horizontally compressed. This paper, combined with monitoring data, analysed the cause reason for face-slab damage．

摘要： 蓄水初期，三板溪面板坝在低水位正常运行约18个月，水位蓄高时，大坝相继出现了渗漏量增大等异常情况，后经水下检查，发现其中12 块面板一、二期面板分缝处出现水平挤压破损。本文根据监测数据并结合实际情况分析了面板破损的原因。