【摘要】：近年來(lái)我國(guó)對(duì)山區(qū)河流水力資源的開(kāi)發(fā)利用力度越來(lái)越大,因此對(duì)山區(qū)河流水沙特征的研究也顯得越加重要。當(dāng)在河流中建造水庫(kù)等擋水建筑物后,下游的水流泥沙條件發(fā)生了改變,床面會(huì)遭受清水沖刷而導(dǎo)致河床粗化現(xiàn)象。對(duì)沖刷粗化現(xiàn)象的研究是研究河床演變和解決各種水電樞紐下游工程問(wèn)題的關(guān)鍵。本文首先對(duì)卵石床面的特性進(jìn)行了分析。卵石床面常見(jiàn)于山區(qū)河流中,它相較于沙質(zhì)床面和卵石夾沙床面有著不同的特性。文章具體分析了卵石床面中卵石運(yùn)動(dòng)的非恒定性、粗化層的特征及其形成原因、粗化現(xiàn)象的不同類型以及河流沿程細(xì)化現(xiàn)象等。為了詳細(xì)研究上述現(xiàn)象,本文進(jìn)一步設(shè)計(jì)了清水沖刷卵石床面的水槽物理試驗(yàn)。試驗(yàn)選用粒徑范圍3-50mm的連續(xù)級(jí)配卵礫石作為試驗(yàn)沙,在長(zhǎng)17m、寬0.58m、深0.5m的水槽中進(jìn)行了三組不同流量的清水沖刷試驗(yàn),測(cè)算了床面沖刷深度和粗化層級(jí)配,對(duì)卵石床面在清水沖刷作用下的變化進(jìn)行了分析。此外,本文從起動(dòng)流速出發(fā),定義了一個(gè)臨界最大起動(dòng)粒徑,并據(jù)此提出了一個(gè)針對(duì)卵石床面的粗化層級(jí)配預(yù)報(bào)方法,該方法計(jì)算相對(duì)較為簡(jiǎn)易。將該方法與試驗(yàn)結(jié)果及其他實(shí)測(cè)資料進(jìn)行驗(yàn)證,結(jié)果精確度較高。
[Abstract]:In recent years, the development and utilization of hydraulic resources in mountain rivers have become more and more intensive, so the study on the characteristics of water and sediment in mountain rivers is becoming more and more important. When the reservoir and other water retaining structures are built in the river, the downstream flow and sediment conditions have changed, and the bed surface will be washed away by clear water, which will lead to the river bed coarsening. The study of scour coarsening is the key to study the river bed evolution and solve the downstream engineering problems of various hydropower hubs. In this paper, the characteristics of the pebble bed are analyzed. Pebble bed surface is common in mountain rivers, which has different characteristics compared with sandy bed surface and gravel sand bed surface. This paper analyzes concretely the unsteady movement of pebble in the cobble bed, the characteristics of coarsening layer and its forming reasons, the different types of coarsening phenomenon and the phenomenon of river thinning along the course, etc. In order to study the above phenomena in detail, a flume physical test was designed to wash the pebble bed with clear water. The continuous gradation gravel with 3-50mm particle size was selected as test sand. Three groups of clean water scour tests were carried out in a flume of 17m in length, 0.58m in width and 0.5m in depth. The scour depth of bed surface and the gradation of coarse gradation were calculated. The change of pebble bed surface under the action of clean water was analyzed. In addition, starting from the starting velocity, a critical maximum starting particle size is defined, and a prediction method of coarsening gradation for the cobble bed is proposed, which is relatively simple to calculate. The method is verified with the experimental results and other measured data, and the accuracy of the results is high.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TV147;TV149

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王思瑩;段文剛;李利;;寬級(jí)配非均勻沙運(yùn)動(dòng)特性研究[J];人民長(zhǎng)江;2011年13期

2 王協(xié)康;楊青遠(yuǎn);王憲業(yè);劉興年;劉同宦;;卵石床面清水沖刷穩(wěn)定形態(tài)及其水流結(jié)構(gòu)試驗(yàn)研究[J];四川大學(xué)學(xué)報(bào)(工程科學(xué)版);2006年03期

3 何文社,曹叔尤,張紅武,劉興年;清水沖刷河床穩(wěn)定粗化層級(jí)配計(jì)算[J];水力發(fā)電學(xué)報(bào);2003年02期

4 孫志林,孫志鋒;粗化層試驗(yàn)與預(yù)報(bào)[J];水力發(fā)電學(xué)報(bào);2000年04期

5 師哲,龍超平;葛洲壩樞紐下游河段河床演變分析[J];長(zhǎng)江科學(xué)院院報(bào);2000年01期

6 許全喜,張小峰,談廣鳴;河床沖刷粗化多步預(yù)報(bào)模式研究[J];水科學(xué)進(jìn)展;1999年01期

7 李榮,李義天,王迎春;非均勻沙起動(dòng)規(guī)律研究[J];泥沙研究;1999年01期

8 秦榮昱,胡春宏,梁志勇;沙質(zhì)河床清水沖刷粗化的研究[J];水利水電技術(shù);1997年06期

9 胡海明,李義天;河床沖刷粗化計(jì)算[J];泥沙研究;1996年04期

10 冷魁，，王明甫;河床沖刷粗化的隨機(jī)模擬[J];水科學(xué)進(jìn)展;1994年02期

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