Abstract: The damblocks of 15, 17 and 19 are the discharge orifice blocks, and cracks appeared before deep outlet base plate concrete pouring, especially the dam block 15 was worst. The No. 1 crack, 11- meter far way from upstream face and belowthe elevation of 347.5 was 11.5- meter deep. Cracks threatened the structural safety of cantilever beamand measures were took, such as prestressed cable, embedded anchor rod and chemical grouting. Jetting were found around the prestressed cable on the dam block 15 in the April 2007. Monitoring data showed that the cracks were changing slowly but the jetting was increasing. Quantitative analysis showed that the jetting was related to water level and time effect but not temperature. Jetting would shorten the life of cable, anchor rod and steel so that should be treated, to ensure the safety and durability of the dam.

摘要： 摘要: 白山拱坝15、17、19 号坝段为泄洪深孔坝段。这三个坝段在未浇筑深孔底板混凝土之前均产生裂缝, 15 号坝段最为严重, 其中位于347.5 m 高程以下坝体与悬臂体产生的1 号裂缝( 距上游面11.0 m) 最深, 深达11.5 m。裂缝已对悬臂体结构安全构成威胁, 在施工中采取加预应力锚索、铺设索定钢筋、埋设锚杆、化学灌浆等综合措施进行了处理。2007 年4 月发现15 号坝段预应力锚头周边射水。监测表明, 裂缝测值变化稳定, 但射水量有增加趋势。定量分析结果, 射水量与水库水位、时效关系明显