大型串联渠系冰塞-水力响应特性分析

为了定性定量描述南水北调中线工程冰塞特征与水力响应特性之间的耦合关系，采用数值模拟方法，建立了串联渠系冰塞事件-水力响应-闸门操作耦合响应模型，通过多工况对比揭示冰塞体范围、厚度和输水流量及闸门群应对方式等造成的渠系水力响应规律。研究结果表明：闸门群耦合响应下，发生冰塞事件的渠池仅影响其上游渠池的水力过程，对于发生冰塞事件的渠池，其冰塞体上游段水位壅高，下游段水位降低，而该渠池上游所有渠池水位整体降低；闸门群无响应时，冰塞可造成渠系放空风险，而PI控制器作用下的闸门群调度可明显改善渠系应对冰塞事件的水力响应，水位波动幅度随冰塞体和输水流量的增大而不断增大，在模拟工况下，闸前最大水位偏差达0.5 m，输水目标恢复时间约20 h，在冰塞体足够大时，渠系面临漫堤风险。做好渠池风险评估和优化冰塞事件应对控制器是下一步研究的重点。

Hydraulic response of large tandem canal system under ice jam effect

In order to describe the coupling characteristics between ice jam and the hydraulic response of the middle route of the South-to-North Water Diversion Project, the coupling response model of ice jam evolution-hydraulic process-sluice operation was established by the numerical experiment. The study revealed the hydraulic response of canal system under different extent and thickness of ice jam, the water flow and the gate operation. The results showed that under the coupling response of the gate group, the ice jam only affected the hydraulic process in upstream canals. For the canal pool where ice jam occurs, the upstream water level rose continuously, and the downstream water level reduced, but the water level in other upstream pools decreased. When all gates operation was constant, the ice jam can cause the risk of canal venting, and the gate operation under the action of the PI controller can significantly improve the hydraulic response. In this condition, the water level fluctuation increased with the increase of ice jam and water flow. Under the simulated working conditions, the maximum water level fluctuation before the gate reached 0.5m, and the recovery time of the water delivery target was about 20h, indicating that when the ice jam is large enough, the canal is exposed to the risk of overflow. Thus, the risk assessment and optimization of canal response controller needs a further study.