Abstract: The monitoring data of outlet at Pubugou hydropower station under construction were analysed in this paper. As well, the cause reason for instability of surrounding rock in construction was found out and deformation characteristics were introduced here. At present, deformation of emptying tunnel surrounding rock is convergent, physical monitoring indexes are of the downward trend.

摘要： 详细分析了瀑布沟水电站放空洞施工期的监测成果，并对施工期围岩的局部失稳原因进行了分析，阐述了施工期围岩变形特征。目前放空洞围岩变形已趋于收敛，监测物理量呈下降趋势。