- 作者: 徐鐵良
- 作者服務機構: 台灣省地質調查所
- 中文摘要: 蘇花公路自蘇澳至花蓮長約115公里。此路原為遜清督軍羅大春於1874年率領兵工修建之行人道路,後經日人拓建為單線公路。台灣光復後,迭經修整始有今日規模。本路線三分之二以上道路皆沿太平洋岸海崖經過。沿線山區皆為上古生代至中生代之大南澳片岩所分佈。路線標高,除河谷平原之外,皆在海拔200--250公尺左右。沿線海崖之標高,自700公尺至1200公尺。此區之年雨量為2600--2700公釐,北段雨量稍多。 蘇花公路每當霪雨之後發生山崩,交通隨即中斷影響甚大。山崩發生之原因乃由於地形之陡峻,變質岩岩質之脆弱,及雨水之?刷。此外,波浪與河流之侵蝕,亦足以削弱公路基礎之穩定,強烈地震之搖撼,常亦觸發山坡之崩坍。蘇花公路山崩之方式主要可分為岩石之滑落,岩石崩落與及岩屑之滑落等。大致言之,岩石滑落多發生於公路北段片岩地區,而岩石之崩落則常見於南段之片麻岩地區。岩屑之滑落則係見於岩屑或礫石堆積層中。陡坡上岩體含水飽和後,內在磨擦阻力減低,遂易發生坍落。故水量含蓄較多之時,容易招致山崩之發生。 預防山崩方法頗多,就蘇花公路而論,凡易於山崩之處,可以考慮改線採取隧道通過,或加強護坡設施與改善當地之水土保持。公路附近採石場應與公路線保持一定之距離,以免採石場之開挖,危及山坡之穩定以導致山崩損害。
- 英文摘要: The Suao-Hualien highway located along the Pacific coast in northeasternTaiwan is 115 km long. The highway is built along the precipitous coast offault origin, consisting a number of sea cliffs of '700-1200 m in elevation. Landslides have been a serious problem to the single-lane highway be-cause it is often damaged by landslides and the transportation services beinterrupted from time to time. The area between Suao and Hualien is distributed mainly by the meta-morphic complex of the Tananao Schist which consists of gneisses, crystal-line limestone, and various types of schist. Since the occurrence of thefractured metamorphic rocks in the region of steep topography, landslidesare especially developed. Other causes responsible for the landslide are theintense rainfall and the earthquake shocks which are main agents in crea-ting major sliding. Landslides along the Suao-Hualien highway may be classified into fourtypes: the rock slides, debris slides, slumps, and rock falls, among whichrock slides are more extensive than the others. Rock falls are especiallydeveloped in the southern part of the highway where the crystalline lime-stone and gneisses are distributed. For preventing the damages caused by landslides relocation of the high-way through tunnels is likely the best way to be followed. Otherwise, theside slopes be protected by proper structures. The improvement of surfacedrainage and soil conservation are also helpful. The quarry sites presentlynearby the highway should be kept in a suitable distance.
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