NETSTARS 模式加入橋墩沖刷功能之研究─以八掌溪為例

This study applies NETSTARS V3.0 by adding the calculation functions of eighteen pier scour formulas based on a comprehensive literature review to demonstrate local scour mechanisms. The study area is a reach of the Pachang Creek from the Housheng Bridge to the Chukou Bridge. We do not set the structures and weirs in the river to be scoured. Simulations are conducted by setting boundary conditions and importing information about nineteen bridges, and validations are separated into two steps as: general scouring and bridge local scouring. The best parameters are qualified by computing error evaluated parameter to fit the changing tendencies of the Pachang Creek. Finally, long-term riverbed evolution is simulated. The results show that there are 5 bridges with erosion trends. The results can be used as a reference for one-dimensional numerical models with pier scouring functions.本研究以NETSTARS V3.0 功能為基礎，根據橋墩沖刷研究，撰寫橋墩沖刷功能並新增18 個常用的橋墩沖刷公式於模式中。研究區域為八掌溪厚生橋至觸口橋河段。在輸砂模式建置上，將結構物設定為不可沖刷，並輸入邊界條件與現有19 座橋樑資訊，完成一般沖刷與局部沖刷階段之參數檢定，並利用誤差評估參數檢視最佳參數以反應八掌溪流域河床變遷趨勢。最後對未來十年河床沖淤進行預測，推測有沖刷趨勢的橋樑共5 座，研究成果可作為一維數值模式新增橋墩沖刷功能之參考