本文選題：淤積特性 + 入渠特性　； 參考：《內(nèi)蒙古農(nóng)業(yè)大學》2014年碩士論文

【摘要】：引黃渠道的泥沙淤積問題是當今水工程界極為關(guān)注并致力于研究解決的重要問題。本文以內(nèi)蒙古鐙口引黃揚水灌區(qū)總干渠為研究對象，分別對2012年和2013年四個灌水期泵站開、停泵時取水口前的泥沙淤積厚度以及運行期間抽水流量、入渠含沙量及渠道各斷面含沙量進行了觀測，根據(jù)觀測數(shù)據(jù)，依據(jù)水力學和泥沙理論，對取水口及總干渠的泥沙淤積問題進行了分析研究。 研究內(nèi)容主要包括取水口泥沙淤積特性和入渠特性、總干渠泥沙的輸移與淤積、沉降與懸移特性，含沙量變化規(guī)律及其與各影響因素間的關(guān)系等。研究結(jié)果表明： （1）取水口淤積情況取決于取水流量、取水口的分流寬度、泵站停泵時間等。取水流量越大，取水口分流寬度越大，泵站停泵時間越短，，取水口前淤積厚度越小；取水口的淤積厚度分布呈現(xiàn)上游大于下游的趨勢，即取水主流區(qū)偏向下游，流速比η越大，這種趨勢越明顯。 （2）影響黃河泥沙入渠的主要因素包括開泵時取水口前的淤積狀況、流速比η以及取水口分流寬度等。開泵時取水口前淤積厚度越大，流速比η越小，取水口分流寬度越大，推移質(zhì)入渠量越大。取水口前設(shè)置攔沙坎可有效阻止推移質(zhì)入渠。 （3）水流速度、懸移流速及起動流速之間存在三種關(guān)系，相應(yīng)渠道處于沖刷、淤積和不沖不淤狀態(tài)。含沙量的變化規(guī)律呈現(xiàn)沿程降低、沿程增加、變化平緩和起伏較大四種狀態(tài)。渠道含沙量S與各影響因素的相關(guān)性由強到弱分別為流速/U、懸移質(zhì)沉速/、床沙中值粒徑/D50床、水深/h和懸移質(zhì)中值粒徑/D50懸。其中S與U、、D50懸呈冪函數(shù)關(guān)系，與h呈線性函數(shù)關(guān)系，與D50床呈指數(shù)函數(shù)關(guān)系。 （4）懸移質(zhì)挾沙能力占總挾沙能力的比重較大，推移質(zhì)挾沙能力占總挾沙能力的比重較小。影響懸移質(zhì)（推移質(zhì)）挾沙能力的粒徑不僅是懸移質(zhì)（推移質(zhì)）粒徑，還與床沙粒徑有關(guān)。懸移質(zhì)和床沙粒徑均較小時，懸移質(zhì)和推移質(zhì)挾沙能力均較大。 （5）利用Van Rijn公式進行渠道挾沙能力的計算，與實測結(jié)果相關(guān)性較好。故本文采用該方法進行挾沙能力和淤積量計算。
[Abstract]:The siltation of the Yellow River diversion channel is an important problem which the water engineering field pays close attention to and devotes to solve. In this paper, taking the main trunk canal in Inner Mongolia's stirrup mouth as the research object, the silt deposition thickness of the four pumping stations in 2012 and 2013 before the opening and stopping of the pump intake and the pumping flow during the operation are respectively studied. The sediment content in the channel and the sediment concentration in each section of the canal were observed. According to the observed data, the siltation problem of the intake and the main canal was analyzed and studied according to the hydraulic and sediment theory. The main contents of the study include the characteristics of sediment siltation and the characteristics of entering the canal, the transport and deposition of sediment in the main channel, the characteristics of sedimentation and suspension, the variation law of sediment content and the relationship between sediment content and the influencing factors, etc. The results show that: The siltation of the intake depends on the water flow, the width of the diversion, the pump stop time and so on. The larger the intake flow, the larger the diversion width, the shorter the pump stop time, the smaller the deposition thickness before the intake, the larger the distribution of sediment thickness is upstream than the downstream, that is, the lower the flow velocity is, the lower the velocity is. The more obvious this trend is. 2) the main factors affecting the silt flow into the channel of the Yellow River include the siltation condition before the intake, the velocity ratio 畏 and the diversion width of the intake when the pump is opened. When the pump is opened, the bigger the deposition thickness is, the smaller the velocity ratio 畏 is, the wider the diversion width is, and the larger the bed load is. The sand bar before the intake can effectively prevent the bed load from entering the canal. 3) there are three relationships among flow velocity, suspended velocity and starting velocity, and the corresponding channel is in the state of scouring, siltation and no scouring and no silting. The change rule of sediment content shows four states: decrease along course, increase along course, change slowly and fluctuate greatly. The correlation between the sediment content S and the influencing factors from strong to weak is velocity / U, suspended sediment sedimentation velocity, bed sediment median particle diameter / D _ (50) bed, water depth / h and suspended sediment mean particle diameter / D _ (50) suspension respectively. Among them, the relationship between S and UD50 is a power function, a linear relationship with h, and an exponential function with a D50 bed. (4) the proportion of suspended sediment carrying capacity to total sediment carrying capacity is larger, and the proportion of bed load sediment carrying capacity to total sediment carrying capacity is relatively small. The particle size which affects the sediment carrying capacity of suspended sediment is not only the particle size of suspended sediment, but also the particle size of bed sediment. The particle size of suspended sediment and bed sediment are both small, and the carrying capacity of suspended sediment and bed load is larger. 5) the calculation of sediment carrying capacity by Van Rijn formula has a good correlation with the measured results. Therefore, the method is used to calculate the sediment carrying capacity and silting capacity.
【學位授予單位】：內(nèi)蒙古農(nóng)業(yè)大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TV146

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