淤地坝排洪渠—溢洪道组合式泄洪过流的物理试验和数值模拟

Physical Test and Numerical Simulation of Flood Discharge Process Combined Flood Channel with Spillway of Check Dams

为探究排洪渠连接溢洪道的过流形式能否适用于满淤积状态下的淤地坝,采用物理模型试验与数值模拟相结合的方法,研究了排洪渠—溢洪道组合形式对淤地坝减蚀、泄洪能力的影响。结果表明,在该连通方式下,坝地及溢洪道内整体水流平稳,仅在溢洪道进口前出现紊乱流态;排洪渠的布设减小了坝地的径流流速,可有效抑制洪水对淤积土体的冲刷侵蚀破坏;在上游来流量较小时,溢洪道的流量系数小于设计值,但随着流量增大,淤地坝泄流能力增强并满足泄洪要求。研究结果可为后续淤地坝的除险加固工程提供参考依据。

In order to study the applicability of flood channel connecting with the spillway to the check dams under the high siltation state,the model experiments combined with numerical simulations were used to study the influence of the above forms on reducing erosion and flood discharge for check dams.The results show that under this connection mode,the overall flow pattern over the field and spillway is stable.There is a turbulent flow pattern only in front of the inlet of the spillway;The layout of flood channels reduces the runoff velocity over the field,which can effectively suppress the soil erosion caused by floods;When the upstream flow is low,the discharge coefficient of the spillway is less than the design value.But with the increase of flow,the overflow capacity of check dams will be enhanced and meet the overflow requirements.