差異侵蝕岩石邊坡之調查與穩定分析－以台2線68k附近邊坡為例

Investigation and Stability Analysis of Differential Erosion Rock Slope: Example of the Slope at 68K of Provincial Highway No. 2

楊士賢(Shih-Hsien Yang) ； 詹佩臻(Pei-Chen Chan) ； 林承翰(Cheng-Han Lin) ； 林錫宏(Hsi-Hung Lin) ； 徐明志(Min-Chih Hsu) ； 溫廷睿(Ting-Rui Wen) ； 林銘郎(Ming-Lang Lin)

《中華水土保持學報》 46卷1期 (2015/03) Pp. 38-46

https://doi.org/10.29417/JCSWC.201503_46(1).0005

摘要

2013年8月基隆八斗子一場豪大雨，造成岩石邊坡發生落石險些擊中車輛事件。該地區屬大寮層而邊坡出露該層中段及下段，其抗風化能力不同造成差異侵蝕現象，使岩塊倒懸成為落石潛勢較高的區域。為減少落石災害影響生命財產安全，本文提出因差異侵蝕形成之倒懸岩坡的落石型態及影響範圍之分析流程與評估方法：包括地形與環境地質調查、運動學理論分析、靜定分析及評估落石影響距離等，透過研究得知此次事件屬於張力破壞的翻倒落石。

關鍵字

差異侵蝕 ； 倒懸邊坡 ； 邊坡單元劃分 ； 靜定分析

並列摘要

On August 31, 2013, a huge rock driven by torrential rain fell on Provincial Highway No. 2 in Badoutzu and nearly hit a passing car. In Badoutzu, the Da-liao Formation is exposed on the rock slope. The strength of the middle part is greater than that of the lower part; therefore, a notch propagates along the lower part during erosion, resulting in rockfall potential at the middle part. To reduce or avoid rockfall hazard, we recommend a method and associated procedures to analyze the mechanics and the influence area of a rockfall event, that is slope unit division, stereographic projection analysis, stability analysis, and rockfall run-out distance estimation using RocFall Software. The proposed method reveals that the event of August 31 was a tensile-failure-induced toppling.

並列關鍵字

Differential erosion ； overhanging rock ； slope unit division ； stereographic projection analysis ； analysis of statically determinate structures