台2線68K八斗子落石災害致災成因初探

基隆市北寧路於2013年8月31日下午發生高強度降雨事件（最高達94.5 mm/hr），並導致台2線68K+000處於當日16時19分左右發生落石擊毀小客車之意外。本次落石災害之發生區屬於大寮層中段塊狀砂岩，且為逆向坡之型態，現地調查結果顯示本區域具有兩組傾角近乎垂直之節理面，一組走向約略平行於海岸線，另一組走向則約略垂直於海岸線。致災成因可能與長期雨水入滲及風化作用有關，節理裂隙除因風化作用逐漸加大外，節理面上之含鐵質結核亦可能於風化後體積增加，進而加速節理開裂速度。本次落石災害之運動歷程大致可分為傾倒、滾動、墜落、彈跳、滾動等數段歷程，落石運動過程耗時約23秒，移動路徑上之植被與風化土壤層可能為遲滯落石運動之主因。本文將說明此次災害之地質調查成果，並探討可能之破壞機制，以供未來類似災害之防治對策參考。

關鍵字

落石；地質調查；破壞機制

並列摘要

Several rockfalls caused damages on Highway No.2 during an intensive rainfall on August 31, 2013, in Keelung. One of the rockfalls hit a car and the event was captured by a camera. This study analyzes the mechanism of the rockfall based on the video and field investigation. Two major joints which led to the hazard, one was parallel to the coast and the other was perpendicular to the coast. Both of them were almost vertical and cut the rock into several blocks. Weathering processes may have lead to the extension of joints during the heavy rainfall; the infiltration and the surface runoff took the weathered material away, making the rock unable and ultimately leading to the rockfall. The process of this hazard can be divided into topple, roll, fall, bounce and roll. The rockfall took about 23 seconds in total. This paper focuses on the results of field investigation and the mechanism of the rockfall is also discussed.

並列關鍵字

Rockfall ； geological investigation ； failure mechanism

被引用紀錄

鄭憲聰（2014）。應用分離元素法於台二線邊坡災害模擬〔碩士論文，國立臺北科技大學〕。華藝線上圖書館。https://www.airitilibrary.com/Article/Detail?DocID=U0006-2008201415522700

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台2線68K八斗子落石災害致災成因初探

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