泄槽体型对溢洪道泄流能力的影响

Influence from chute body shape on spillway discharge capacity

以密云水库第一溢洪道为例,利用经验公式、数值模型、物理模型试验模拟三种方法研究了收腰与等宽两种泄槽体型溢洪道的典型库水水位对应的最大泄量,讨论了下游泄槽体型对泄流能力的影响,对比了三种方法计算结果的准确性。定量分析结果表明:溢洪道泄流能力受泄槽体型的影响,等宽泄槽比收腰泄槽泄流能力强,推荐采用等宽泄槽方案;经验公式计算的泄流能力偏差较大,数值模型模拟结果偏差较小且偏于保守,建议大型水利工程前期论证均采用数值模拟的方法,从而保证水库防洪安全。

By taking the No.1 spillway of Miyun Reservoir as the study case,the maximum discharges corresponding to the typical reservoir water levels for both the waist-shaped chute and the chute with uniform width are simulated through three methods,i.e. empirical formula,numerical model and physical modeling experiment;from which the influence from the body shape of the downstream chute on the discharge capacity is discussed,while the accuracies of the calculation results from the three methods are compared. The quantitative analysis result shows that the discharge capacity of spillway is affected by the body shape of chute,while the discharge capacity of the chute with uniform width is stronger than that of the waist-shaped chute,thus the chute with uniform width is recommended to be adopted. The deviation of the discharge capacity calculated from empirical formula is a little bit too large,but the deviation of the simulation result from numerical model is a little bit less and conservative,thus it is suggested to adopt numerical simulation for all the prophase demonstrationsof large-sized water conservancy projects.