Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/13893
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dc.contributor.advisor陳正炎zh_TW
dc.contributor.advisorJen-Yan Chenen_US
dc.contributor.author林宏宇zh_TW
dc.contributor.authorLin, Hung-Yuen_US
dc.date2001zh_TW
dc.date.accessioned2014-06-06T06:51:25Z-
dc.date.available2014-06-06T06:51:25Z-
dc.identifier.urihttp://hdl.handle.net/11455/13893-
dc.description.abstract本研究參酌既有堰壩投潭水流作用於河道渠床局部沖刷之相關研究,針對在堰壩鋪設護坦(apron)、水墊(water cushion)及副壩(secondary dam)等消能設施(energy dissipators)其下游沖刷現象探討之,藉由變換不同消能設施的佈置尺寸進行渠槽試驗,瞭解沖刷坑特性與不同消能設施之相對關係,以及其對下游床面之沖刷保護功效,並利用消能的觀念來剖析兩者相互間之關係。 研究結果發現若以消能觀點而言,水墊工法由於水流在靜水池內相互碰撞,因而相較於護坦工法更具保護效果,並以尾檻高度特徵因子β=0.13者為佳;副壩工法因於副壩上下游均為動床,故宜以系統前後能量變化剖析沖刷特性。無論剛性或柔性消能設施所形成沖刷坑之損失能量,均呈現隨坡度變陡而增大之趨勢。又剛性消能設施皆能有效降低沖刷坑之最大刷深及體積量,其中水墊工法之坑長消減率平均約為40%,沖刷體積量消減率至少達40%;護坦工法雖無法減小坑長,卻能將沖刷現象均勻減緩至下游地區達保護功效,而在緩坡時對減低刷深與體積量仍具不錯效果。另以副壩工法為之,若主副壩間距過小,易造成主副壩間渠床劇烈之淘刷,建議採主副壩間距特徵因子α>1.56為宜。在本試驗條件下,提出一簡易消能設施特徵尺度關係式供相關單位參考,期能對消能設施之規劃設計上有所助益。zh_TW
dc.description.abstractAccording to the related research about the scouring effects of free over-fall will be used in this study. The situation will be discussed in steady flow by using different energy dissipators — apron, water cushion and secondary dam. Facilities, the protected effect and the comparative characteristics of scouring hole will be found (such as the max. depth, max. length, shape factor and volume) in downstream of the energy dissipators. The result would be determined by energy dissipating theory, which is the relations between the scale of dissipators and energy variation. In view of energy disspators, the water cushion had the result of protection better than apron, because of the current hits mutually at the water pond. And the height factorβ=0.13 is the best. The situation of the secondary dam is the moving bed, therefore analysis of the scouring characteristic to make use energy variety of system. In both the rigid and soft energy disspators, the energy loss of scouring increased with slop. The degree of scouring depth and volume could be lowered effectively in rigid energy disspators. In water cushion, the average decreased rate of the scouring length about is 40 percent, and the scouring volume quantity decreases rate reaches 40 percent at least. Although, scouring length can't be decreased at apron disspators. The scour phenomenon be mollified to a downstream region for protective effects. Scouring is more serious between major and secondary dam if the distance is too short from both of them. Character factorα>1.56 is the suggested application. In this experiment condition, a simple formula is proposed for a relevant establishment. It is expected to be helpful in designs of energy disspators.en_US
dc.description.tableofcontents誌謝 I 摘要 II 英文摘要 III 目錄 IV 圖目錄 VI 表目錄 IX 相片目錄 X 符號說明 XI 壹、前言 1 1.1研究動機 1 1.2研究目的 2 1.3本文組織 3 貳、文獻回顧 5 2.1相關文獻 5 2.1.1消能設施 5 2.1.2流場顯性特徵 7 2.1.3流場隱性特徵 11 2.2.文獻整理分析 12 2.2.1消能設施探討 13 2.2.2沖刷坑特性分析 15 2.2.3能量損失與沖刷現象 18 參、渠槽試驗 22 3.1試驗依據與規劃 22 3.2試驗設備與儀器 25 3.2.1渠槽設備 25 3.2.2量測儀器 26 3.2.3輔助工具 28 3.3試驗步驟與方法 28 3.3.1預備試驗 28 3.3.2正式試驗 31 3.4試驗假設與條件 37 肆、試驗結果與分析 39 4.1沖刷試驗結果 39 4.1.1剛性消能設施 39 4.1.2柔性消能設施 40 4.2沖刷坑特性 43 4.2.1剛性消能設施 43 4.2.2柔性消能設施 73 4.3能量觀點分析 80 4.3.1剛性消能設施 80 4.3.2柔性消能設施 86 4.4消能設施優選評估 91 4.4.1單項評估 97 4.4.2整體評估 98 伍、結論與建議 100 參考文獻 103 作者簡介 106zh_TW
dc.language.isoen_USzh_TW
dc.publisher土木工程學系zh_TW
dc.subjectapronen_US
dc.subject護坦zh_TW
dc.subjectwater cushionen_US
dc.subjectsecondary damen_US
dc.subjectenergy disspatorsen_US
dc.subject水墊zh_TW
dc.subject副壩zh_TW
dc.subject消能設施zh_TW
dc.title消能設施對防砂壩下游局部沖刷影響之研究zh_TW
dc.titleA Study on Energy Dissipators and Local Scouring in Downstream of Check Damen_US
dc.typeThesis and Dissertationzh_TW
item.openairecristypehttp://purl.org/coar/resource_type/c_18cf-
item.languageiso639-1en_US-
item.grantfulltextnone-
item.cerifentitytypePublications-
item.openairetypeThesis and Dissertation-
item.fulltextno fulltext-
Appears in Collections:土木工程學系所
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