高含沙水流作用下水垫塘底板上举力特性试验

针对高含沙水流对水垫塘底板上举力特性的影响,通过模型试验,研究了不同含沙量下底板上举力的分布规律、幅值特性和频谱特性。结果表明:含沙水流作用下的上举力沿程分布规律与清水时相同;各流速下上举力时均值均随含沙量的增大而增大,且基本呈线性函数关系,斜率在0.17～0.22之间;上举力标准差随含沙量的增大先增大后减小,在含沙量为183 kg/m~3时出现峰值;上举力的脉动在0～3 Hz的低频范围内,与清水相比,水流含沙后功率谱的频带宽度增加,高频域内的功率谱密度值有所增加;水流的时间积分尺度随着含沙量的增大呈先增大后减小的趋势。

Experiment on characteristics of uplift acting on a plunge pool slab in high sediment-laden flow

Aiming at the influence of high sediment-laden flow on the uplift characteristics of a plunge pool slab, the distribution, magnitude and spectrum characteristics of the uplift force under different sediment concentrations was studied by model test. The results show that the distribution of the uplift force on the plunge pool in sediment-laden flow is similar with that in clean water. For each flow rate, the mean value of the uplift force increases with the increase of the sediment concentration, and basically shows a linear function with a slope between 0. 17 and 0. 22. The standard deviation of the uplift force increases first and then decreases with the increase of sediment concentration, and the standard deviation of the uplift peaks at the critical sediment concentration of 183 kg/m³. The pulsation of the uplift force is in the low frequency range of 0~3 Hz, but compared with the clean water, the frequency band width of the power spectrum increases and the power spectral density in the high frequency domain increases when sediment is added to water. The time integral scale of the flow increases first and then decreases with the increase of sediment concentration.