水电站大坝运行期防洪安全常见问题分析

Analysis on Flood Control Safety of Hydropower Dam during Operation Period

防洪问题是水电站大坝运行安全评价中最为关注的一个问题。目前大坝运行安全防洪评价中的常见问题有:防洪标准不符合现行规范,运行过程发生大洪水或强降雨导致运行期实际洪水超过原设计标准,土石坝沉降导致坝顶(防浪墙顶)高程不满足现行规范。据此提出运行期大坝防洪问题的解决方法,包括加高坝顶(防浪墙顶)高程,增建泄洪设施增大泄流能力,限制运行条件(降低汛限水位、增加泄水量、限制上游水库运行等)和联合调度等。

Flood control is one of the most concerned problems in dam operation safety evaluation of hydropower stations.The common problems in flood control evaluation of dam operation safety are discussed as following:the flood control standard does not meet current standards,the actual flood exceeds the original design codes due to large flood or heavy rainfall during operation,and the elevation of dam crest(wave wall top)does not meet current specifications because of earth rock dam settlement.The main solutions to flood control of dams in operation period are also put forward in several aspects:heightening the elevation of dam crest(wave wall crest),improving flood discharge facilities,increasing discharge capacity,limiting operation conditions(reducing flood control water level,limiting operation of upstream reservoir,etc.)and joint operation,etc.