2023年甘肃积石山6.2级地震灾害特征

Characteristics of Disasters Caused by the Jishishan Mg6.2 Earthquake in Gansu Province in 2023

2023年12月18日,甘肃省临夏州积石山县发生6.2级地震,震源深度10km。此次地震造成了大量人员伤亡。地震强度较大,建筑结构、非结构构件震害严重;生命线系统多见破坏;场地灾害主要表现为土壤液化、山体崩塌、液化流滑,其中以金田村的液化流滑现象尤为突出。与2018年印尼帕鲁7.5级地震、1303年洪洞8.0级地震、1920年海原8.5级地震相比,此次地震液化流滑现象具有低角度、大范围、长距离的显著特征。现场调查分析发现,充分的水利补给、物源区的明显凹陷是导致本次地震液化流滑规模巨大的原因,且此次流滑与2018年帕鲁地震流滑现象有多处相似之处,但两者流滑机理上存在着本质的不同,值得后续深入研究。对于此次地震,美国地质调查局给出的人员伤亡及场地破坏预测偏向保守,急需发展匹配抗震设防能力的震害预测方法。

On December 18,2023,an earthquake of magnitude 6.2 struck Jishishan County,Linxia Prefecture,Gansu Province,with an epicenter depth of 10km.The earthquake,due to its large intensity,caused a large number of casualties,serious damage to building structures and non-structural components and damaged lifeline system.The main forms of site disasters were soil liquefaction,mountain collapse and liquefaction slip,with the liquefaction and slip phenomenon in Jintian Village being particularly prominent.Compared with the 2018 Palu M7.5 earthquake,the 1303 Hongdong M8.0 earthquake and the 1920 Haiyuan M8.5 earthquake,the liquefaction flow-slip phenomenon of the 2023 Jishishan earthquake features low angle,large range and long distance.On-site investigations show that sufficient water conservancy recharge and obvious depression in the provenance area are main reasons for the huge scale of liquefaction flow-slip induced by this earthquake.Besides,many similarities exist between the flow-slip of the Jishishan MS6.2 earthquake in Gansu Province and that of the 2018 Paru M7.5 earthquake,in spite of the essential differences existing in their flow-slip mechanisms,which are worthy of further study.Since prediction of the casualties and site damages caused by this earthquake given by the United States Geological Survey is conservative,there is an urgent need to develop earthquake damage prediction methods that match seismic fortification capacities.