本文選題：堰塞壩 + 漫頂溢流�。� 參考：《中國水土保持科學(xué)》2017年06期

【摘要】：由于潰口各處水沙作用差異較大,不同位置的展寬過程不同,目前對潰口展寬過程的研究多著眼于某一斷面,不但不能反映潰口整體的展寬過程,還會影響潰決流量計算的精度。為研究不同壩高、壩后坡比條件下潰口整體展寬過程,本研究設(shè)計了6組水槽實驗,分析了45個斷面的觀測數(shù)據(jù),發(fā)現(xiàn):1)潰口展寬隨溢流的發(fā)展表現(xiàn)出不同的形式,以溯源侵蝕的結(jié)束為時間節(jié)點,溯源侵蝕期間為近等寬階段,溯源侵蝕結(jié)束后為彎曲階段。2)在斷面上,展寬模式可分為線性模式和突變模式,分別占45個斷面的13.3%與86.7%;突變模式進一步可分為弱侵蝕過程Ⅰ和強侵蝕過程Ⅱ,其中強侵蝕過程只發(fā)生在彎曲階段。3)突變模式下,過程Ⅰ侵蝕率沿程呈首尾大-中部小的"U"型分布,潰口首部和潰口尾部侵蝕率較大,中間近等寬段侵蝕率有所減小,壩后坡比越大,該過程中潰口相同位置處的侵蝕率越大;隨著溢流的發(fā)展,水流結(jié)構(gòu)復(fù)雜,具有明顯的二次流特征,導(dǎo)致過程Ⅱ的侵蝕率沿程分布呈"S"型;對2個過程而言,壩高越高,相同位置處的侵蝕率越大。上述對于堰塞壩溢流展寬過程的新認識,有益于今后深入定量研究潰口展寬過程和力學(xué)機理。
[Abstract]:Because the action of water and sediment is very different and the process of widening is different in different positions, the research on the widening process of the burst is mainly focused on a certain section at present, which can not only not reflect the whole widening process of the burst. It will also affect the accuracy of outburst flow calculation. In order to study the whole widening process of the burst under different dam heights and the ratio of the back slope of the dam, this study designed six groups of flume experiments, and analyzed the observation data of 45 sections. It was found that the expansion of the break showed different forms with the development of overflow. Taking the end of traceability erosion as time node, the period of traceability erosion as near equal width stage, and the bending stage at the end of traceability erosion, the broadening model can be divided into linear model and abrupt mode on the cross section. The mutation model can be further divided into weak erosion process 鈪，

本文編號：1991932