Zhao Bo, Wang Yun-Sheng, Luo Yong-Hong, Li Jia, Zhang Xin, Shen Tong
State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu, Sichuan 610059, People's Republic of China.
R Soc Open Sci. 2018 Mar 28;5(3):171418. doi: 10.1098/rsos.171418. eCollection 2018 Mar.
At 21.19 on 8 August 2017, an Ms 7.0 earthquake struck the Jiuzhaigou scenic spot in northwestern Sichuan Province, China. The Jiuzhaigou earthquake is a strike-slip earthquake with a focal depth of 20 km at 33.20° N and 103.82° E, and was caused by two concealed faults. According to emergency investigations and remote sensing interpretations, the Jiuzhaigou earthquake triggered 1780 landslides, damaged one dam (Nuorilang Waterfall) and broke one dam (Huohua Lake). The landslides mainly occurred in the Rize Valley and Shuzheng Valley and in Jiuzhai Paradise. The landslides involved hanging wall and back-slope effects, and the slope angle, slope aspect, seismic faults and valley trend were obviously related to the occurrence of the landslides. Specifically, most of the landslides were shallow landslides, rockfalls and rock avalanches and were small in scale. The failure modes of landslides mainly include wedge rock mass failure, residual deposit failure, relaxed rock mass failure and weathered rock mass failure. The initial low stability of the dam coupled with the topographic effect, back-slope effect and excess pore water pressure led to damage to the Nuorilang Waterfall dam.
2017年8月8日21时19分,中国四川省西北部九寨沟风景名胜区发生7.0级地震。九寨沟地震是一次走滑型地震,震源深度20千米,震中位于北纬33.20°、东经103.82°,由两条隐伏断层引发。根据应急调查和遥感解译,九寨沟地震触发了1780处滑坡,损毁了1座堤坝(诺日朗瀑布),冲垮了1座堤坝(火花海)。滑坡主要发生在日则沟、树正沟以及九寨沟天堂区域。滑坡涉及上盘效应和后坡效应,且坡度、坡向、地震断层和山谷走向与滑坡的发生明显相关。具体而言,大多数滑坡为浅层滑坡、岩崩和岩滑,规模较小。滑坡的破坏模式主要包括楔形岩体破坏、残积层破坏、松弛岩体破坏和风化岩体破坏。堤坝初始稳定性较低,加上地形效应、后坡效应和超孔隙水压力,导致诺日朗瀑布堤坝受损。