水口水电站坝下水位治理工程上引航道水流条件研究

Water Level Treatment Project below the Dam of Shuikou Hydropower Station and Flow Condition of Upper Approach Channel

水口水电站坝下水位治理工程为无闸溢流低坝,小流量时坝前呈现水库水流特征,随流量增大溢流坝逐渐蜕变成潜坝,水流条件近似天然河道,上引航道水流流态差、斜流强。分析了形成该水流特点的原因和对船舶安全过闸的影响;根据分散水流、弱化斜流强度原理,提出分段延长隔流墙、变高度透水孔的方法来改善引航道通航水流条件;通过模型试验观测得知提出的技术方法能够较好地解决引航道水流紊乱、斜流强、通航条件差的问题,将最高通航流量由Q=7 000 m3/s提高至Q=16 900 m3/s。

The water level treatment project below the dam of Shuikou Hydropower Station was a low spillway dam with no floodgate. The flow in front of the dam flow showed the characteristics of reservoir when the flow was small. However,with the flow increasing,the spillway dam became submerged dam. The flow condition was just like the natural river flow,and the flow pattern in upper approach channel was bad and the oblique flow was strong. The causes of the flow characteristics mentioned above and the effect of the flow on the safety of the passage ships were analyzed. According to the theory of dispersing the flow and weakening the strength of oblique flow,the measures of extending the guide wall by segment and placing permeable holes with different heights were put forward. Through the observation of model test,the technical methods proposed here turned out to be effective to solve the problem of flow disorders,strong oblique flow and the bad navigation condition in the channel; and the maximum navigation discharge was improved from Q = 7,000 m3/ s to Q = 16,900 m3/ s.