中国地质灾害与防治学报2023，Vol.34Issue(6)：3-12,10.DOI:10.16031/j.cnki.issn.1003-8035.202209046
甘肃岷县永光1#流滑型黄土滑坡的远程滑动特征
Long-runout characteristics of the Yongguang 1# loess flowslide in Minxian County,Gansu Province
摘要
Abstract
Flowslide in loessic regions,characterized by their elongated shape and tendency to slide and accumulate along channels or gentle hillslopes,frequently lead to devastating and unpredictable disasters.The Yongguang 1# flowslide in Minxian County,Gansu Province,caused by the Minxian-Zhangxian Ms6.6 earthquake at 7:45AM on July 22,2013,claimed twelve lives and had a volume of approximately 23×104 m3.The landslide had a vertical difference of 175m between its front and rear edges,a total length of 1 030 m,and a ratio of 0.17,classifying it as a long-runout landslide.This paper explored the characteristics of the sliding process and the sliding velocities of different portions of the flowslide through field survey and a comprehensive analysis of the observation data of the sliding process,while also analyzing the sliding mechanism.Triggered by earthquake,the runout process of the flowslide has been affected by local terrain.The flowslide experienced two complex sliding stages of acceleration and deceleration.Initially,the landslide slid as a whole in the front platform area for 50 to 130 m,and then the front sliding body with an volume of about 6×104 m3 continued to slide along the front channel for 740 m,resulting in a maximum runout distance of 870 m.The entire sliding process lasted about 7 hours,with a maximum sliding speed of approximately 10.6 m/s,and an average sliding speed of 0.034 m/s.The formation of the Yongguang 1# landslide was influenced by the coupled effects of seismic activity and early-precipitation.The earthquake,preceded by heavy rainfall,led to infiltration and softening of the soil.During the sliding process,the high water content in the sliding zone generated high pore water pressure,and in some cases,liquefaction occurred.The channel-shaped topography and low permeability of the sliding zone soil caused a very slow dissipation of pore water pressure,resulting in a significant reduction in frictional resistance in the sliding zone soil throughout the entire sliding process,with a noticeable velocity-sustaining effect.These factors are the primary reasons for the long-runout of the Yongguang 1# landslide.关键词
流滑型黄土滑坡/远程滑动/孔隙水压力/液化Key words
flowslides in loess/long-runout flowslide/pore water pressure/liquefaction分类
天文与地球科学引用本文复制引用
吴玮江,王国亚,张国信,冯乐涛,姚正学,宿星..甘肃岷县永光1#流滑型黄土滑坡的远程滑动特征[J].中国地质灾害与防治学报,2023,34(6):3-12,10.基金项目
国家自然科学基金项目(42067066) （42067066）
甘肃省科学院项目(2022JK-04) （2022JK-04）
