Characteristics and triggering mechanism of Xinmo landslide on 24 June 2017 in Sichuan, China  

作　　者：SU Li-jun HU Kai-heng ZHANG Wei-feng WANG Jiao LEI Yu ZHANG Chong-lei CUI Peng Alessandro PASUTO ZHENG Quan-hong 

机构地区：[1]Key Laboratory of Mountain Hazards and Earth Surface Process, Chinese Academy of Sciences [2] Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China [2]CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China [3]University of Chinese Academy of Sciences, Bering 100049, China [4]Sino-Italian Laboratory on Geological and Hydrological Hazards, Chengdu 610041, China [5]National Research Council of Italy-Research Institute for Geo-Hydrological Protection, Padova, Italy [6]Sichuan Bureau of Surveging, Mapping, and C-eoinformation, Chengdu 610041, China

出　　处：《Journal of Mountain Science》2017年第9期1689-1700,共12页山地科学学报（英文）

基　　金：financially supported by the National Basic Reareach program of China (973 program, Grant No. 2013CB733201);Key Research Program of Frontier Sciences, CAS (Grant No. QYZDY-SSW-DQC006);the “Hundred Talents” program (SU Li-jun) of Chinese Academy of Sciences (CAS)

摘　　要：At 5: 39 AM on 24 June 2017, a huge landslide-debris avalanche occurred on Fugui Mountain at Xinmo village, Diexi town, Maoxian county, Sichuan province, China. The debris blocked the Songpinggou River for about 2 km, resulting in a heavy loss of both human lives and properties(10 deaths, 3 injuries, 73 missing, and 103 houses completely destroyed). The objectives of this paper are to understand the overall process and triggering factors of this landslide and to explore the affecting factors for its long term evolution before failure. Post event surveys were carried out the day after the landslide occurrence. Information was gathered from literature and on-site investigation and measurement. Topography, landforms, lithology, geological setting, earthquake history, meteorological and hydrological data of the area were analysed. Aerial photographs and other remote sensing information were used for evaluation and discussion. Eye witnesses also provided a lot of helpful information for us to understand the process of initiation, development and deposition. The depositional characteristics of the moving material as well as the traces of the movement,the structural features of the main scarp and the seismic waves induced by the slide are presented and discussed in detail in this paper. The results show that the mechanism of the landslide is a sudden rupture of the main block caused by the instability of a secondary block at a higher position. After the initiation, the failed rock mass at higher position overloaded the main block at the lower elevation and collapsed in tandem. Fragmentation of the rock mass occurred later, thus forming a debris avalanche with high mobility. This landslide case indicates that such seismic events could influence geological hazards for over 80 years and this study provides reference to the long term susceptibility and risk assessment of secondary geological hazards from earthquake.

关 键 词：High-position landslide Xinmo landslide Landslide mechanism Earthquake effects Rock fall Debris avalanche 

分 类 号：P642.22[天文地球—工程地质学] P458.121.1[天文地球—地质矿产勘探]