摘要
为了深入分析2022年1月8日青海门源M_(S)6.9地震引发的不同类型地表破裂特征及震害现象,本文依据沿此次地震地表破裂带进行的野外实地考察和无人机航拍解译,将破裂带沿线的典型同震地表破裂特征归纳为:(1)多种典型几何细结构,包括雁列状次级破裂、左旋左阶拉张区、左旋右阶挤压区以及树枝状、网状破裂等;(2)多种地貌标志物水平位错,包括牧区围栏、车辙印、动物脚印和冲沟冰面的左旋断错等;(3)多种类型垂直破裂,如逆冲型地震陡坎和正断型地震陡坎;(4)多种类型挤压破裂,如挤压脊和挤压鼓包;(5)不同类型张性裂缝带,如纯张性裂缝带和张剪性裂缝带.将地震引发的地质及工程震害现象归纳为:(1)跨地震断裂带的边坡垮塌失稳;(2)跨地震断裂带的公路、桥梁和隧道损坏;(3)地震断裂带附近区域的冰面鼓包、公路裂隙等形变现象.此外,对上述现象的展布特征和成因机制进行了分析讨论,并强调了加强跨活动断裂带时工程抗断及近断层强地面运动的抗震设防的重要性.
At 01:45 on January 8,2022,a M_S6.9 earthquake occurred in Menyuan County,Haibei Tibetan Autonomous Prefecture,Qinghai Province.The epicenter was located at(37.77°N,101.26°E)in Lenglongling area of the central Qilian mountains,with a focal depth of 10 km.According to the comprehensive results of field investigation and aerial image interpretation by unmanned aerial vehicle(UAV),the seismogenic fault of this earthquake undertakes a sinistral strike-slip motion,with a slight thrust component.The surface rupture zone of this earthquake is composed of the north main rupture zone located at the west end of Lenglongling fault and the southwest secondary traction rupture zone located at the east end of Tuolaishan fault.A series of extensional step-overs,sinistral displacements,tensional fractures,compressed bulges,and compressed ridges were formed along the surface rupture zone,resulting in damage to the Lanzhou-ürümqi high-speed railway tunnels and bridges and the suspension of train services.In order to comprehensively analyze the different types of surface fracture features and seismic damage caused by this earthquake,field investigations and aerial interpretation using UAV were conducted along the rupture zone.As a result,typical coseismic surface fracture features along the rupture zone were categorized as follows:(1)Various typical geometric structures,including echelon secondary rupture,sinistral extensional stepovers,sinistral compressed step-overs,dendritic and netlike forked rupture,etc;(2)Horizontal displacement observed in various geomorphic markers,such as left-lateral dislocations in pastoral areas,truck trace,animal footprints,and gullies and gully ice;(3)Various types of vertical rupture,such as thrust seismic scarps and normal seismic scarps;(4)Various types of compressed rupture,such as compressed ridges and compressed bulges;(5)Different types of tensional crack zones,including pure tensional cracks and tensional-shear cracks.The geological and engineering seismic damage caused by the earthquake c
作者
苏瑞欢
袁道阳
谢虹
文亚猛
司国军
薛善余
Su Ruihuan;Yuan Daoyang;Xie Hong;Wen Yameng;Si Guojun;Xue Shanyu(School of Earth Sciences,Lanzhou University,Lanzhou 730000,China;Lanzhou Institute of Seismology,China Earthquake Administration,Lanzhou 730000,China)
出处
《地震学报》
CSCD
北大核心
2023年第5期797-813,共17页
Acta Seismologica Sinica
基金
第二次青藏高原综合科学考察研究(2019QZKK0901)
国家自然科学基金(42172227)
中国电建集团西北勘测设计研究院有限公司平台支撑项目(XBY-PTKJ-2022-5)共同资助。
