利用顆粒體離散元素法模擬莫拉克颱風所引致之新開崩塌

The Transportation of Hsiankai Landslide Induced by 2009 Morakot Typhoon: Insight from a 3D Granular Discrete Element Simulation

10.29417/JCSWC.201503_46(1).0004

謝嘉聲(Chia-Sheng Hsieh)；蕭達鴻(Darn-Horng Hsiao)；唐昭榮(Chao-Lung Tang)；胡植慶(Jyr-Ching Hu)

顆粒 ； 離散元素 ； 新開 ； Granular ； Discrete Element ； Hsiankai ； PFC 3D

中華水土保持學報

46卷1期（2015 / 03 / 01）

29 - 37

繁體中文

高雄市六龜區的新開於2009年莫拉克颱風侵襲期間發生大規模之崩塌，掩埋多處民房及造成多人罹難。估計崩塌塊體之體積約為1百萬立方公尺，崩塌地幾何形狀為源頭及堆積區二端廣大，但傳輸區狹窄。顆粒體離散元素法模擬崩塌的結果顯示，整個塊體並非在同一時間崩落，而是由下端先裂後逐漸向上發展。源頭區的碎屑由二側向中央集中，再順著狹窄的通道而下。到達堆積區後，由於碰撞消能作用，速度急速下降，摩擦係數上升，因此碎屑向外擴張。最後，大部份崩落的土石堆積在平地與山坡的地方，只有少部份的土石流進荖濃溪。整個過程約120秒，碎屑滑動速度最高可達每秒40公尺。

A catastrophic landslide in Hsiankai (Liugui District, Kaohsiung City) was induced by 2009 Morakot Typhoon. Many house and inhibits were buried by the landslide debris, causing many victims. The volume of the landslide debris was about 1 million m^3. The geometry of the landslide is wide in the source and deposit zones, and narrow in the transportation zone. By using a granular discrete element simulation model, our result shows that the whole block doesn't slide down simultaneously. Instead, the sliding starts from the bottom of the block, then moves upward. In the source area, debris falls toward a center, and then rushes through a narrow passage, the transportation zone. When the debris reaches the deposit zonedue to collision-induced energy dissipation, the velocity of the landslide debris decreases rapidly, and the friction coefficient increases. Therefore, the debris spreads out at the deposit area. Most of the debris deposits on the toe of the slope, and few of the debris slides into the Launong River. The duration of the landslide is about 120 seconds. The maximum velocity of the landslide debris is 40m/sec.