2022年青海门源M S_(6.9)地震灾害致灾机理  

THE DISASTER MECHANISM OF THE M S_(6.9)EARTHQUAKE IN MENYUAN,QINGHAI PROVINCE,2022

作　　者：牛鹏飞 韩竹军[1] 郭鹏[1] 李科长 吕丽星 NIU Peng-fei;HAN Zhu-jun;GUO Peng;LI Ke-chang;LU Li-xing(Institute of Geology,China Earthquake Administration,Beijing 100029,China)

机构地区：[1]中国地震局地质研究所,北京100029

出　　处：《地震地质》2024年第4期761-782,共22页Seismology and Geology

基　　金：中国地震局地质研究所基本科研业务专项(IGCEA2206);国家自然科学基金(42002231)共同资助。

摘　　要：2022年门源M S_(6.9)地震发生在青藏高原东北缘祁连-海原断裂带冷龙岭和托莱山断裂的阶区部位。兰新高铁硫磺沟大桥及南侧大梁隧道被完全毁坏,致使高铁干线首次因地震破坏而完全中断。在地处极震区的硫磺沟内未见大规模地震滑坡和崩塌,只有规模较小的滚石和滚石堆积体及局部河床存在砂土液化现象,显然很不合常理。此次地震除形成2条走滑型地表破裂带外,还在冷龙岭断裂西段北侧的硫磺沟内产生了1条长约7.9km的逆冲型地表破裂带。该破裂带的走向不稳定,倾向S,主要由断续分布的弧形挤压破裂、挤压鼓包、张裂隙和地震陡坎组成;经统计,沿地表破裂带共获得了35个垂直位移量数据,最小位移量为(8±1)cm,最大位移量为(49±3)cm,平均垂直位移量约为24cm,位移沿走向分布不均匀。该条地表破裂带近垂直穿过兰新高铁硫磺沟大桥,产生了宽泛的地表变形与位错,这可能是导致硫磺沟大桥毁坏的直接原因。这些调研成果启示我们在对跨断层重大线状工程进行抗震设防时,需要关注逆冲型地表破裂带宽泛的剪切作用。Earthquake disasters are one of the most significant natural disasters faced by human society.Understanding and mitigating earthquake disasters have always been a key focus of research for seismologists.Conducting investigations on post-earthquake seismic disasters is of great significance for the recovery and reconstruction of disaster-stricken areas,as well as for earthquake prevention and mitigation.Earthquake disasters can be classified into two types based on their mechanisms:one is the destruction caused directly by the seismic vibrations on buildings,lifelines,and other structures;the other is the damage related to geological hazards triggered by earthquakes.The former is mainly related to the density of regional economic layout;the latter seismic geological disasters typically include collapses,landslides,debris flows,ground fissures,ground subsidence,and soil liquefaction.These geological disasters often exacerbate the impact of seismic disasters,posing a more significant threat to human life and property safety.Therefore,it is of great significance to investigate the mechanisms of significant engineering disasters caused by earthquakes,as it can provide important insights for engineering recovery,reconstruction,and site selection.The Qilian-Haiyuan fault zone is an important boundary fault on the northeastern margin of the Qingzang Plateau.It plays a crucial role in absorbing and accommodating the convergence of the Indian Plate towards the Eurasian Plate in a NNE direction.With a total length of approximately 1000km,it is primarily composed of the Tolaishan fault,the Lenglongling fault,the Jinqianghe fault,the Maomaoshan fault,the Laohushan fault,and the Haiyuan fault,from west to east.On January 8,2022,a magnitude 6.9 earthquake occurred near the stepover of the Longling and Tuolaishan faults of the Qilian-Haiyuan fault zone.Although the earthquake occurred in uninhabited,sparsely wooded alpine grasslands and did not cause any casualties,it completely destroyed the Liuhuanggou bridge and the south-sid

关 键 词：门源M S_(6.9)地震 地震地表破裂带 地震灾害 工程抗震设防 

分 类 号：P315.2[天文地球—地震学] P315[天文地球—固体地球物理学]