全光纖式邊坡穩定監測系統整合與現地應用測試(2/4)

Abstract

目前針對潛在性及滑動中之邊坡監測，大多採用傳統傾斜管配合手動式傾斜儀監測滑動面之所在位置及滑動量，監測地下水位則多使用開口式水位計。這些監測儀器幾乎全部使用手工，在儀器現場紀錄讀數。此一安排不但費時，在雨季或邊坡發生滑動時時，現場紀錄儀器讀數可能無法進行或非常危險，而這些情況下也可能是最需要監測儀器讀數的時候。近年來雖有可做自動化監測之電子式監測儀器之研發，但電子式自動化監測系統具有價格昂貴、易受電磁波干擾、雷擊破壞、且儀器設備若長期處於潮濕環境容易短路故障等缺點。光纖相較於電子式儀器的優點在於訊號傳輸距離遠可達數十公里及在光纖傳輸線上可連接多點或分佈式之感測器。本計畫將以阿里山台18線公路五彎仔路段作為本試驗之場址，使用本研究團隊研發之光纖感測地層移動監測系統與分佈式光纖水壓計來監測該地區之地層滑動及水壓變化，並配合地下水文數值模型分析，以作為該地滑區日後穩定評估之依據。

For monitoring slopes that are potentially unstable or where sliding is progressing, the inclinometer casings are typically used. Open end piezometers are commonly used to monitor ground water levels. Readings from these instruments are mostly taken in the field manually. The procedure is time consuming and hazardous during the rainy season or when the slope is unstable. The potential danger may prevent the critical instrument readings be taken when they are needed the most. Many automated electronic devices have been developed recently. These devices are mostly expensive and subject to electromagnetic interferences, lightning and deterioration when deployed in the field. In comparison with electronic devices, the optic fiber sensors can easily transmit signals by tens of kilometers through light. Multiple sensors can be connected to a single optic fiber. A test site will be set up at the Five Turn Point of Highway 18 near Alishan. The fiber optic ground displacement and ground water monitoring sensors developed by the research team will be deployed at the test site. Coupled with field measurements, a ground water flow numerical model will be established for future studies.