基於降雨量之邊坡崩壞預警系統－以阿里山公路邊坡為例

ESTABLISHING THE RAINFALL-BASED WARNING SYSTEM FOR SLOPE FAILURE IN ALISHAN HIGHWAY

李德河(Der-Her Lee) ； 王國榮(Kuo-Jung Wang) ； 陳允哲(Yun-Che Chen) ； 吳建宏(Jian-Hong Wu) ； 曾致仁(Zhi-Ren Tseng)

《中國土木水利工程學刊》 31卷7期 (2019/11) Pp. 643-657

https://doi.org/10.6652/JoCICHE.201911_31(7).0005

摘要

本文以進入阿里山森林遊樂區前方2,000公尺的一處曾經產生小規模崩塌，並經穩定處理的公路邊坡（台18線86 k + 950）為對象，在邊坡上設置一系列的地下水位井、傾斜觀測管等監測設備，並連結中央氣象局阿里山雨量站的降雨觀測，取得該公路邊坡的降雨量－地下水位變動的關係，並由Geo-Studio軟體分析公路邊坡的安全係數與地下水位變動的關係，求得使安全係數= 1的臨界地下水位，再由降雨量－地下水位變動的關係圖中，探討可使邊坡的地下水位達到臨界狀態時所須要的降雨量之上、下限，並依此分辨讓邊坡處於安全、可能崩塌（0 ＜ 破壞機率 ＜ 100%）及崩塌（破壞機率 = 100%） 等狀態時之累積降雨量（ΣR），進而為此試驗邊坡建立以降雨量為基礎的豪雨防災預警系統，其內容為：安全階段（ΣR＜366mm）警戒階段（366 mm ≦ ΣR ＜ 599 mm）避難階段（599 mm ≦ ΣR ＜ 882 mm）災害階段（882 mm ≦ ΣR ＜ 1,116 mm）災難階段（1,116 mm ≦ ΣR）

關鍵字

降雨量 ； 邊坡崩壞 ； 預警系統 ； 阿里山公路

並列摘要

This study investigates a highway slope 2 km ahead of the entrance of Alishan National Forest Recreation Area and is located at the mileage of 86 k + 950 of the Alishan Highway. Artificial countermeasures were conducted after a slope failure. Groundwater wells and inclination wells are installed on the slope. The relations between rainfall and groundwater fluctuation are obtained by analyzing the groundwater elevation and the rainfall data from the Alishan rainfall station. In addition, the relations between the slope stability and the groundwater level are assessed by the Geo-Studio software to obtain the groundwater level with the critical state of the slope. Then, the rainfall-groundwater level figure indicates the upper and lower bounds of the rainfall to result in the slope critical state. Next, the cumulative rainfall (ΣR) corresponding to the following three slope stability stages: stable, possible failure (0 ＜ failure possibility ＜ 100%), and slope failure (failure possibility = 100%) can be determined. Therefore, the rainfall-based slope warning system is shown as follows: (1) Safety (ΣR ＜ 366 mm), (2) Warning (366 mm≦Σ R ＜ 599 mm), (3) Refuge (599 mm≦ΣR ＜ 882 mm), (4) Disaster (882 mm≦ΣR ＜ 1,116 mm), (5) Catastrophe (1,116 mm≦ΣR).

並列關鍵字

rainfall ； slope failure ； warning system ； Alishan Highway

參考文獻

公路總局第五區養護工程處(2012).(公路總局第五區養護工程處,「2012 年度公路防救災檢討年報」,嘉義 (2012).).

李德河,田坤國,黃嵩傑,林國忠(1996).賀伯颱風引致阿里山公路低海拔路段邊坡變動之觀測調查.地工技術雜誌.57,81-91.

呂政諭(2001).地震與颱風作用下阿里山地區公路邊坡崩壞特性之研究(碩士論文).國立成功大學土木工程研究所.

Chang, M. S.,Chiu, Y. F.,Lin, S. Y.,Ke, T. C.(2005).Preliminary study onthe 2003 slope failure in Woo-Wan-Chai area, Mt. Ali Road, Taiwan.Engineering Geology.80,93-114.

Lin, H. M.,Chang, S. K.,Wu, J. H.,Juang, C. H.(2009).Neural network-based model for assessing failure potential of highway slopes in the Alishan, Taiwan area: pre- and post-earthquake investigation.Engineering Geology.104,280-289.