| 门源M6.9地震诱发地质灾害特征研究 |
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| 引用本文： | 王谦,钟秀梅,高中南,马金莲,万秀红,杨义煊,刘岸果.门源M6.9地震诱发地质灾害特征研究[J].西北地震学报,2022,44(2):352-359. |
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| 作者姓名： | 王谦 钟秀梅 高中南 马金莲 万秀红 杨义煊 刘岸果 |
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| 作者单位： | 1. 中国地震局(甘肃省)黄土地震工程重点实验室;2. 甘肃省地震局;3. 青海省地震局 |
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| 基金项目： | 国家自然科学基金项目(51778590)； |
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| 摘 要： | 2022年1月8日发生的门源M6.9地震诱发了崩塌、滑坡、砂土液化、地裂缝等多种同震地质灾害。通过对门源M6.9地震地质灾害进行现场调查，得出了地质灾害的分布特征和各类型地质灾害的主要特点，分析了地震地质灾害不发育的原因，并对地震地质灾害的长期效应进行了分析预测。研究结果表明：门源地震诱发地质灾害主要分布在震中附近；崩塌、落石总体规模较小，滑坡多为岩质滑坡，且以冰碛物和表层岩土体的溜滑为主。受表层土体冻结和孔隙水压力消散的影响，饱和砂土液化沿较窄的地裂缝呈串珠状分布，喷出物多为粉细砂。地震形成了4条左旋左阶斜列的地表破裂带，并在极震区内形成了大量的地裂缝。断层破碎带对地震动的阻隔作用、覆盖层薄、地表土冻结可能是造成本次地震地质灾害总体不发育的主要原因；地震产生的大量地裂缝导致斜坡和堆积体的稳定性减弱，在耦合集中降雨、冻融作用等因素后可能诱发滑坡灾害，松散堆积于沟床处的崩滑物作为物源，可能会增加地震影响区泥石流灾害的风险。
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| 关 键 词： | 崩塌 滑坡 砂土液化 地裂缝 长期效应 |
| 收稿时间： | 2022/2/17 0:00:00 |
Characteristics of geological hazards induced by the Menyuan M6.9 earthquake |
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| WANG Qian,ZHONG Xiumei,GAO Zhongnan,MA Jinlian,WAN Xiuhong,YANG Yixuan,LIU Anguo.Characteristics of geological hazards induced by the Menyuan M6.9 earthquake[J].Northwestern Seismological Journal,2022,44(2):352-359. |
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| Authors: | WANG Qian ZHONG Xiumei GAO Zhongnan MA Jinlian WAN Xiuhong YANG Yixuan LIU Anguo |
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| Institution: | 1.Key Laboratory of Loess Earthquake Engineering of China Earthquake Agency & Gansu Province, Lanzhou 730000, Gansu, China;2.Gansu Earthquake Agency, Lanzhou 730000, Gansu, China;3.Qinghai Earthquake Agency, Xining 750000, Qinghai, China |
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| Abstract: | The Menyuan M6.9 earthquake occurred on January 8, 2022, induced many kinds of co-seismic geo-hazards, i.e., collapses, landslides, sand liquefaction, and ground fissures. Based on the field investigation results, the distribution and characteristics of various types of geological disasters induced by the M6.9 earthquake were obtained in this paper. Besides, the reasons for the undeveloped seismic geo-hazards were analyzed, and the long-term effects of seismic geo-hazards were predicted. The results showed that the geo-hazards induced by the M6.9 earthquake are mainly distributed near the epicenter. The collapses and rockfalls are not big. Most of the landslides are rock landslides, which are dominated by the sliding of moraine and surface rock and soil. Due to the freezing of surface soil and the dissipation of pore water pressure, the liquefaction of saturated sand is beaded along narrow ground fissures, and the ejecta is mostly silty and fine sand. Four sinistral oblique surface rapture zones and a large number of ground fissures are formed in the meizoseismal area. The barrier effect of fault fracture zone on strong motion, thin overburden layer, and freezing of surface soil may cause the undevelopment of seismic geo-hazards. A large number of ground fissures generated by the earthquake weaken the stability of slopes and accumulation bodies, which may induce landslides under the coupling action of concentrated rainfall and freezing-thawing cycles. In addition, loose deposits in gully beds generated by collapses and landslides may increase the risk of debris flow in earthquake-affected areas. |
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| Keywords: | collapse landslide sand liquefaction ground fissure long-term effect |
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