Development of an Innovative Bridge Scour Monitoring System

臺灣地處亞熱帶海島型氣候區，受到季風影響及經常性的颱風侵襲，每年均有豐沛的降雨量，加上本島地形條件特殊，山高谷深、河川坡陡流急，因此跨河橋梁基礎結構長期普遍存在自然沖刷的現象。而橋梁基礎即時沖刷深度，是評估現地跨河橋梁結構穩定性的重要指標，如何掌握現地橋梁基礎即時沖刷資訊，探討跨河橋梁於可能最大沖刷深度發生時的使用狀態安全性，提供相關橋梁權責管理單位於可能發生災害前應變作業參考，是自然災害防治重要的研究課題之一。本研究目的為開發一套具創新性的現地橋梁基礎沖刷監測系統，並將其建置於現地橋梁進行實測研究，研究方法主要基於近幾年研究團隊應用創新感測技術開發現地橋梁基礎即時沖刷監測系統之經驗，藉由實驗室水槽試驗驗證所開發元件之量測機制可行性，並將開發之量測元件加以設計封裝保護，使其符合現地橋梁監測系統安裝及量測使用需求。研究開發成果包含光纖光柵式沖刷感測元件及微機電壓力感測元件並將其整合於無線感測網路進行橋墩即時沖刷深度量測技術應用，研究成果已獲得相關技術專利肯定。而本論文著重之橋梁沖刷監測技術開發研究工作具有整合土木工程、資訊工程及電機機械工程等跨領域研究的特性，藉著相關整合性工作階段性成果，針對目前已開發之感測元件和應用系統的後續研究執行工作極具參考價值。研究結論除驗證所開發元件之量測機制可行性外，並透過系統現地建置試辦應用，掌握開發階段系統於現地應用時需注意之安裝程序及項目，而許多現地量測資訊及安裝系統之效能仍有賴持續性的研究開發進行改善，諸如各式感測元件於現地條件下之耐久性、洪水或沖刷事件發生時量測資料之可靠性以及現地資料傳輸系統和電源供給模組長期應用的穩定性等。面對現地橋梁沖刷監測研究議題艱鉅的挑戰及研究成果實用的迫切性，接續本研究成果，研究團隊仍持續規劃針對橋梁沖刷破壞機制做試驗探討，並開發和應用可定量之感測元件，利用目前已安裝於現地之系統回饋資訊進行研究改善。The hydraulic causes of bridge failure have focused engineering attention on the bridge scour problem. However, in-situ bridge scour monitoring is still one of the rugged works for field application researchers. Especially for Taiwan, the island which is well known for its distinctive topography features that the central mountain range bisects the main territory from north to south leading to most rivers have short courses and rapid streams. This dissertation summarizes the development work that has been undertaken by the research team on in-situ bridge scour monitoring system in recently years. Fiber optical grating sensors, micro-electro-mechanical systems based pressure sensors and vibration-based detection sensors are applied to develop an innovative scour monitoring system for over water bridges. Several experimental results in the laboratory have proven the technologies developed could provide the scour-depth information near bridge foundation structures by using qualitative measurement deploy. Besides, practical experimental projects are also described in this study. The in-situ projects have brought up the preliminary implementation of installations of the system on field applications, which significantly contribute the useful feedback and the verification result to the development work of this research. Furthermore, the problems with challenge of running integrated projects are briefly mentioned. Though the actual performance of the scour monitoring system currently developed in this research needs time to be further verified and improved to meet the practical requirements for monitoring bridge scour under harsh environmental condition, this research indicates the importance of the bridge scour monitoring issues and propose a feasible way to do the further study for continued development work