丹江口大坝加高工程下游河床冲刷坑成因分析

丹江口大坝为满足南水北调中线一期工程引水的需要,需加高13 m。初期工程泄洪调度贯彻了先开深孔,后开表孔的原则,根据记录,深孔泄洪9~11坝段的3~8孔泄洪历时最长,下游河床受到了一定程度的冲刷,并形成了多处冲刷坑。目前,下游河床冲刷在深度上已稳定,但往上游、东侧两方向仍有发展。大坝加高后,挑距加大,可能在下游侧产生严重冲刷,并且冲刷坑最低点向下游侧移动;深孔坝段可能使目前的冲刷坑加深,并向下游河床扩展。为了保证大坝安全运行,需要采取相关的工程处理措施。

Downriver Scouring Pit Origin Analyzed in the Project of Raising the Danjiangkou Dam

In order to meets the needs of the South-to-North Water Diversion Project,the Danjiangkou dam need to be raised 13 meters.In the initial period of the project,flood discharges dispatch the principle that open the deep hole first then followed by the table hole.According to the record, flood charge in the deep hole 9-11 dam of hole 3-8 experience the longest time, the downriver bed received the certain degree of flushing,and formed many pits.Now the downriver scouring already stabilized in depth,but the scour will move to the upstream and the East direction.In order to make the dam operates safety;we need to adopt the appropriate measure.