| 摘要: | 目前台灣地區橋梁所面臨的三大考驗為老劣化、地震及洪災，更又因全球氣候變遷及極端氣候的影響，近年豪大雨發生機率頻繁，更有如莫拉克颱風所引致的八八水災等對南台灣的肆虐，橋梁的管理與維護工作，對結合量測與分析技術的橋梁健康診斷系統的需求益形重要。 橋梁上部結構常因鋼筋腐蝕、預力鋼腱鏽蝕或鬆弛等劣化現象影響橋梁承載力與其服務壽命，然而各種劣化因子對橋梁的影響評估，往往採用非破壞檢測或監測技術予以評定，本研究發展應用於橋梁載重試驗與健康監測系統的變位量測方法，利用光纖光柵感測技術，建立一套具備高精度與高耐久性的多點同步變位量測系統，可量測橋梁上構大梁因荷載作用的撓度曲線，亦可監測懸臂橋因預力鬆弛所產生的撓度變化量，且利用長期監測數據分析橋體應變與溫度變化的關係性，更成功建立一套以橋梁作為簡易地磅的監測系統，統計計數分析橋梁所受的荷載譜。 對於橋梁下部結構，沖刷為其主要潛在的破壞影響因素，尤以台灣河短流急，橋墩更常因沖刷造成損毀，本文提出一套改良應用壓電薄膜作為感測器的量測系統，用以量測洪水衝擊下橋墩的刷深速率、最大沖刷深度以及河床回淤量。此系統利用壓電材料所製成的壓電薄膜作為感測器，不需供給電源是其最大的優點，再加上結合自重式量測桿，免除鑽孔埋設感測器的需求，更大幅降低建置成本。 跨河橋梁常因沖刷引致落橋事件發生，若落橋事件發生於夜間且伴隨大雨時，視線不良的狀況下容易造成行車駕駛無法辨別前方路況而發生災害，本文發展了一套利用簡單的導線迴路偵測方法，用以偵測斷橋事件發生與否，並結合Zigbee無線通訊技術建立自動化落橋偵測警示系統。 Bridges in Taiwan are currently facing three major challenges, namely the deterioration, earthquakes and floods. The heavy rain was more often occurred in recently years, because of the global climate change. Therefore, the bridge health diagnostic system with measuring and analysis technique is more important for bridge management and maintenance. The loading capacity and service life of bridges are usually impaired by reinforcement corrosion, tendon corrosion or tendon relaxation. Non-destructive tests and monitoring techniques are usually used to determine the impact of loading capacity and service life of bridges. This research has developed serval methods to measuring the deflections of bridges using in bridge loading test and bridge health monitoring system. The bending gauges are used to develop a deflection measuring system of bridges. By linking bending gauges and connecting tubes as a sensing chain, this system can measure multiple locations of deflections caused by static or dynamic load at the same time. Also, the deflections of bridges caused by tendon relaxation can be measured either. An upgraded piezoelectric film type real-time scour monitoring sensor installed along the bridge pier is presented. The core idea of developing this scouring sensing system is based on the physical character that output voltage can be generated as the piezoelectric film is deformed by the flowing media. The piezoelectric film embedded in the soil of riverbed is undisturbed and the output voltage is much smaller than the one disturbed by the water current. From the output signals of all the piezoelectric sensors with known locations along the depth of the pier foundation, one can trace the variation of the soil/water interface before, during and after a flood. Compared with other types of scouring sensors, this piezoelectric type scouring sensor is working without power, durable, sensitive, real-time and cost effective. In this research, a signal processing technique and performance tests in laboratory of this novel piezoelectric film type scouring device are introduced first. This research also presents a bridge monitoring and prewarning system for collapse detection. The system consists of six units: (1) Tilt and Collapse Detection Unit, (2) Power Supply Unit, (3) Image Unit, (4) Alarms Unit, (5) Communication Unit, and (6) Central Control Unit. The system monitors pier tilting as the early warning signal of bridge collapse. Once a pier tilts more than its predefined thresholds, a warning message will be sent to cell phones of relevant bridge management personnel. If any section of the bridge collapses, the system will automatically activate alert sounds and flash lights installed on the bridge, and will also display warning texts on two LED boards installed at both ends of the bridge. |
