二維軟弱岩盤河道沖刷模式之研發與應用

Development and Application of 2-D Soft Bedrock River Incision Model

廖仲達(Chung-Ta Liao) ； 葉克家(Keh-Chia Yeh) ； 陳春宏(Chun-Hung Chen)

《中國土木水利工程學刊》 23卷2期 (2011/06) Pp. 237-244

https://doi.org/10.6652/JoCICHE.201106_23(2).0010

摘要

台灣河川具有坡陡流急、沖淤劇烈之特性，當河床表層之礫石層受到破壞時，常造成底部之軟岩裸露，進而出現嚴重之河床沖刷現象，影響河防安全。目前一般河道沖淤之數模研究，多著重在沖積層與傳統輸砂行為之模擬，而軟岩河道之沖刷過程有別於一般沖積層河道，既有河道輸砂模式多不適用於此問題。本研究開發具有軟岩沖刷機制之水平二維動床模式，以濁水溪集集攔河堰下游河道為例，進行模式檢定、驗證與敏感度分析，結果良好，此一模式可作為軟岩河道治理規劃應用上之參考，而敏感度分析可提供參數與軟岩沖刷機制選用之建議。

關鍵字

軟岩河道沖刷 ； 數值模式 ； 濁水溪 ； 集集攔河堰

並列摘要

Steep slopes and severe bed changes are the channel characteristics in Taiwan's rivers. These characteristics often cause the bed armor layer flushed away, then make the soft bedrock exposed, increase the channel incision, and endanger the safety of prediction works. Hydraulic models of past few decades often aimed at the simulation of alluvial channel's sediment transport. However, the soft bedrock river incision processes are different from those of alluvial rivers. In this study, a 2-D soft bedrock incision model was developed. The study case is the downstream reach of JiJi Weir of Choshui River. Model calibration, validation, and sensitivity analysis were executed. The comparison of the calculated bed changes with field data shows the numerical model is capable of predicting bedrock incision in complex river bed, with reasonable accuracy and reliability. The sensitivity test provides the suggestion of selecting important parameters in the bedrock incision model.

並列關鍵字

soft bedrock incision ； numerical model ； choshui River ； JiJi Weir