Efects of Tectonic Setting and Hydraulic Properties on Silent Large‑Scale Landslides: A Case Study of the Zhaobishan Landslide,China  

作　　者：Shufeng Tian Guisheng Hu Ningsheng Chen Mahfuzur Rahman Huayong Ni Marcelo Somos‑Valenzuela 

机构地区：[1]Key Lab of Mountain Hazards and Surface Processes,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610299,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Academy of Plateau Science and Sustainability,Xining 810016,China [4]Kathmandu Center for Research and Education,Chinese Academy of Sciences-Tribhuvan University,Beijing 100101,China [5]Department of Civil Engineering,International University of Business Agriculture and Technology(IUBAT),Dhaka 1230,Bangladesh [6]Department of Civil Engineering,Kunsan National University,Gunsan 54150,Republic of Korea [7]Institute of Exploration Technology,China Geological Survey,Chengdu 611734,China [8]Department of Forest Sciences,Faculty of Agriculture and Environmental Sciences,Universidad de La Frontera,4780000 Temuco,Chile

出　　处：《International Journal of Disaster Risk Science》2023年第4期600-617,共18页国际灾害风险科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.U20A20110);the Second Tibetan Plateau Scientifc Expedition and Research Program(STEP)of China(Grant No.2019QZKK0902);the Youth Innovation Promotion Association CAS(ID 2020367);the International Cooperation Overseas Platform Project,Chinese Academy of Sciences(Grant No.131C11KYSB20200033).

摘　　要：Unlike strong earthquake-triggered or heavy rainfall-triggered landslides,silent large-scale landslides(SLL)occur without signifcant triggering factors and cause unexpected signifcant disaster risks and mass casualties.Understanding the initiation mechanism of SLLs is crucial for risk reduction.In this study,the mechanism of the Zhaobishan SLL was investigated,and the SLL was jointly controlled by weak-soil(fractured rock mass)and strong-water(abundant water replenishment)conditions under the impact of active tectonism and complex hydraulic properties.Strong tectonic uplift,high fault density,and historical earthquakes led to weak-soil conditions conducive to the Zhaobishan SLL.The combined efect of unique lithology,antiform,and cultivated land contributed to the water replenishment characteristics of extensive runof confuence(3.16 times that of the landslide body)and supported long-distance groundwater replenishment,thereby forming strongwater conditions for the landslide.The amplifed seepage amount caused the strength of the soil mass on the sliding surface to decrease to 0.4 times its initial strength,eventually triggering the Zhaobishan SLL,which occurred 4.6 days after the peak rainfall.Moreover,the landslide deposits have accumulated on the semi-diagenetic clay rock,thereby controlling the subsequent recurring debris fows in the Lengzi Gully.To reduce disaster risk of SLL in vulnerable mountainous regions,the water confuence area behind the main scarp of the landslides and the hysteresis characteristics between landslides and peak rainfall should be further considered,and recurring debris fows following massive landslides also should be focused.

关 键 词：Debris fow Hydraulic properties Risk reduction Runof amplifcation Silent large-scale landslides(SLL) Tectonic setting 

分 类 号：P64[天文地球—地质矿产勘探]