阿里山森林鐵路災害調查及復建規劃

The Investigation of the Failure Mechanisms and Repair Planning of the Alishan Forest Railway

李嶸泰(Jung-Tai Lee) ； 蕭丁槐(Ding-Kuai Ziao) ； 黃崇仁(Chong-Ren Huang) ； 楊宏志(Hong-Zhi Yang) ； 沈宜慶(Yi-Ching Shen)

《中華水土保持學報》 43卷2期 (2012/06) Pp. 123-138

https://doi.org/10.29417/JCSWC.201206_43(2).0003

摘要

阿里山森林鐵路大部分地段位於國有林地，常因颱風、豪雨、地震等因素，發生山崩、地滑及土石流等災害。98年莫拉克颱風重創臺灣，並造成阿里山森林鐵路數處路段之邊坡坡體大規模崩塌。本文選定二處災害較嚴重之路段，藉由地質調查、鑽探及現況調查災害分析，擬定可行之治理模式，以作為復建工程設計之參考。二萬坪崩塌區之岩層傾向與坡向相同，形成順向坡，為古崩塌地，崩塌類型屬大規模且深厚崩積層滑動及逕流沖蝕之複合型破壞。而多林崩塌區之岩層傾向山體，與坡向相反，形成逆傾坡，惟因節理發育且連續性佳，與坡面形成岩楔，易造成崩落，崩塌類型主要為岩盤崩解、崩積層滑動及逕流沖蝕之複合型破壞。由於此二區之崩塌規模甚大，不易進行全面性之植生復育與坡面保護，故建議均採用隧道方案通過崩塌區，以達永續經營之目標。

關鍵字

阿里山森林鐵路 ； 莫拉克颱風 ； 大規模崩塌 ； 地質調查 ； 複合型破壞

並列摘要

The Alishan Forest Railway has frequently suffered landslides, landslips and debris flows caused by different natural hazards. During Typhoon MORAKOT, several large landslides occurred. In this study, two severely damaged sections were selected as the pilot areas. Geological investigations were conducted to investigate the failure mechanisms. The first selected area is in Erwanping. This area has an old landslide area with a dip slope. The failure mechanisms of this collapsed area include a deep landslide with colluvium material and erosion. The second selected area is the collapsed area in the Duolin area. The rock joints in the slope formed rock wedges which fell down easily. The failure mechanisms of this collapsed area include decomposition of rock stratum, a deep landslide and erosion. After a comprehensive discussion, tunneling transportation is chosen because it is a better way to pass through the collapsed areas and the maintenance of a tunnel is much easier in these collapsed areas.

並列關鍵字

Alishan forest railway ； MORAKOT typhoon ； large-scale landslides ； geological investigation ； complex destruction