溢洪道渠首优化试验研究

Experimental study on optimization of spillway head

为校核初步设计方案的合理性,依据正态模型和重力相似准则建立水工模型,对溢洪道渠首结构进行研究。研究结果表明:通过在溢流堰进口两侧设圆弧导墙来减弱绕流,同时取消侧槽调整段的1m高尾坎,将堰宽增大至34m后,溢洪道泄流能力得到了显著提高。校核水位1 304.71m时,溢流堰泄流474.60m^(3)/s,大于设计值463m^(3)/s,溢洪道泄流能力满足要求;掺气坎掺气充分,掺气空腔稳定贯通,掺气坎与补气竖井尺寸合理;在不改变坎高的前提下,适当减小掺气坎坡度,有助于减弱挑射水舌对泄槽底板的冲击作用;不同工况消力池消能充分,池内发生淹没式水跃,消力池池长满足要求。研究成果为类似工程提供一定的参考。

In order to check the rationality of the preliminary design scheme,a hydraulic model is established according to the normal model and gravity similarity criterion to study the spillway head structure.The results show that the discharge capacity of the spillway is significantly improved by setting circular guide walls on both sides of the inlet of the spillway,canceling the 1m high tail ridge of the side groove adjustment section,and increasing the Weir width to 34m.When the check water level is 1304.71m,the discharge 474.60m^(3)/s of the spillway is greater than the design value 463m^(3)/s,and the discharge capacity of the spillway meets the requirements;the aeration ridge is fully aerated,the aeration cavity runs through stably,and the size of the aeration bucket and the air supply shaft is reasonable;without changing the height of the bucket,properly reducing the slope of the aeration ridge is helpful to reduce the impact of the jet tongue on the floor of the spillway.The energy dissipation of the stilling pool under different working conditions is sufficient,the submerged hydraulic jump occurs in the pool,and the length of the stilling pool meets the requirements.The research results would provide some reference for similar projects.