橋橋梁系統受地震及沖刷作用之非線性行為模擬橋梁受地震力及沖刷力作用下之安全性評估是目前國內工程界所關心的議題，瞭解橋梁在此類複雜荷載作用下之損傷狀態與程度，可以提供橋梁設計及維修時做合理的分析處置。因此本研究總體目標是研發橋梁結構工程與流體互制三維多相流數值模式，以結構受刷蝕及地震動態模擬分析為探討主體，藉由水理參數的改變來評估橋梁結構的非綫性行為，所發展的大型平行計算處理分析程式的模擬成果將與其他子計劃之實驗成果比較，以證實模擬軟體之準確性與效能。三年之研發重點為：第一年： 開發流/固耦合分析功能之軟體Solid Truchas，以便進行柔性離散物體-流體之互制動力行為分析。第二年： 流/固耦合分析程序加入震動台作用模擬功能，同時建立之砂土剪力盒數值模型，並與其他子計劃第一年之分析成果進行比對及相互參考，進行橋梁及洪水互制效應分析。第三年： 進行多橋跨之大型實尺寸計算分析，如不同洪水攻角、定床及動床刷蝕淤積、浮木撞擊、破壞、振動等行為，演示該模式於橋樑工程及水利工程設計與補強所需之訊息。 Numerical Simulation of the Nonlinear Behaviors of Bridge System under Combined Scouring and Seismic Excitations ABSTRACT The safety of bridge under the combined seismic and scouring actions is increasingly concerned topic for engineers in Taiwan. Information of the states and severities of damages under these complicated excitations is very useful to engineers for their design and retrofitting works. The main goal of this project is to develop a computational code that can analyze 3-D multiphase fluid-structural interaction problems. Nonlinear dynamic failure behaviors of bridge structures with various combinations of hydrological conditions, seismic excitations and geographical features of river bed are studied. The capability and accuracy of the developed code will be verified by the research results of other sub-projects under the main project. The work items of each year are listed as following: In the first year of this project, a code named as Solid Truchas will be developed to study the fluid-solid interaction problems containing flexible discrete bodies. In the second year of this project, a shaking table function will be established into the Solid Truchas to simulate those experiments of bridge model with its piers standing in sand shear boxes under earthquake excitations. The validated code will be used to investigate the fluid-structural interaction problems with various hydrological and geographical features. In the third year of this project, large scale problems of bridge with more spans will be studied. Behaviors like the local scouring depth of bridge foundation, erosion and deposition of river bed and vibration and failure of structures by various attack angle of flow and impacted by driftwoods will be investigated to gain some information for the purposes of design and retrofitting works of bridge and hydraulic engineering. 研究期間：9908 ~ 10007
