基於床沙位置分佈特性的泥沙起動及推移質輸移規律研究

INCIPIENT SEDIMENT MOTION AND BED LOAD TRANSPORT LAW BASED ON THE DISTRIBUTION CHARACTERISTICS OF BED SEDIMENT POSITION

泥沙起動及推移質輸移規律對河流動力學的理論發展和水利工程的實際應用具有重要意義。為完善泥沙起動及推移質輸移規律，引入暴露角和隱蔽角的概念，以量化床面泥沙的雙向位置特性；基於泥沙起動全概率概念，考慮泥沙起動模式的影響，建立了同一水流條件下總的泥沙起動全概率、泥沙滾動全概率和泥沙躍移全概率計算公式，量化了Kramer泥沙起動標準，推導了與總的泥沙起動全概率相對應的起動流速公式；基於泥沙滾動全概率、泥沙躍移全概率和推移質運動特徵步長及運動時間，修正完善了Engelund的推移質輸沙率模型，構建了新的推移質輸沙率公式。利用經典的實測資料和經典的公式對本文各公式進行了驗證分析，結果表明本文公式均具有較好的適用性，可以應用於實際工程的分析計算。

Incipient sediment motion and bed load transport are of great significance to the theoretical development of the mechanics of sediment movement and the practical application of water conservancy projects. This paper introduces improvements to the concepts of the exposure and shelter angles to quantify the two-way position characteristics of the bed surface sediment. The total probability of incipient sediment motion was established giving consideration to the influence of sediment initiation mode, such as sediment rolling and lifting under the same flow conditions. The incipient sediment motion standard was redefined using total initiation probability, and an incipient motion velocity formula was derived that reflected the randomness of water flow conditions and the distribution of bed sediment position. Using Engelund's basic model of bed load transport rate as a reference, sediment rolling and sediment transition total probability formula was established. The characteristic step length and movement consumption time of the bed load transport were modified to construct a new bed load transport rate formula. The formulas in this paper have been verified using classic measured data and were found to be applicable in practical engineering analyses.