本文選題：清水沖刷 + 含沙量恢復(fù)　； 參考：《應(yīng)用基礎(chǔ)與工程科學(xué)學(xué)報》2017年03期

【摘要】：水庫修建后,清水下泄將造成壩下游河道處于沖刷狀態(tài),引起河勢調(diào)整,給下游防洪、水資源利用及航運(yùn)等可能帶來一系列不利的影響;由于壩下游清水沖刷過程的復(fù)雜性,沙質(zhì)河床含沙量沿程恢復(fù)規(guī)律一直是河流泥沙動力學(xué)的難度問題之一.基于此,首先本文根據(jù)湍流猝發(fā)理論推導(dǎo)出清水沖刷下沙質(zhì)型河床含沙量沿程恢復(fù)的理論公式,然后利用配置精密儀器的變坡水槽試驗(yàn)進(jìn)行相關(guān)研究,并根據(jù)試驗(yàn)數(shù)據(jù)分析不同條件下垂線平均含沙量沿程恢復(fù)的特性.試驗(yàn)成果顯示,當(dāng)流量、床沙粒徑不變,河床比降為0.5‰、1.0‰與2.0‰時,垂線平均含沙量恢復(fù)過程差異性較小,但隨著沖刷距離發(fā)展α_1(近底處含沙量與垂線平均含沙量比值)遞減而α_2(近底處挾沙能力/垂線平均挾沙能力比值)略有增加,且在清水沖刷發(fā)展過程中α_1是一個逐漸靠近α_2的動態(tài)變化過程;當(dāng)床沙粒徑與河床比降不變,流量越大,水流垂線平均含沙量恢復(fù)飽和的數(shù)值與距離越大,α_1、α_2數(shù)值同樣也越大;當(dāng)流量、河床比降不變,床沙粒徑顆粒越細(xì),含沙量恢復(fù)飽和時的數(shù)值越大,恢復(fù)距離也越長,反之亦然.
[Abstract]:After the reservoir is built, the discharge of clear water will cause the downstream channel of the dam to be scoured, causing river regime adjustment, which may bring a series of adverse effects to the downstream flood control, utilization of water resources and navigation, etc. Due to the complexity of the process of water scouring downstream of the dam, The recovery rule of sediment content along sandy river bed is always one of the difficult problems in river sediment dynamics. Based on this, the theoretical formula of sediment content recovery of sandy riverbed under clear water scour is deduced according to the turbulent burst theory, and then the correlation research is carried out by using the experiment of variable slope flume with precision instrument. According to the experimental data, the characteristics of the average sediment content along the vertical line are analyzed under different conditions. The experimental results show that the difference of the average sediment content recovery process of the vertical line is small when the flow rate and the bed sediment diameter are constant, and the river bed ratio is reduced to 0.5 鈥，

本文編號：1982215