2023年2月6日土耳其7.8级地震液化震害宏观特征初探

Preliminary study on the macroscopic characteristics of liquefaction damage following Turkey M_(w)7.8 earthquake on February 6,2023

地震液化是工程场地在地震中面临的主要威胁,为从液化研究角度探查2023年2月6日土耳其7.8级地震局部震害特点,本文借助地理信息系统(geographic information system,GIS)技术,应用宏观液化等级和宏观液化指数的评估方法,通过对此次地震的液化震害调查影像资料分析,阐释了此次地震中场地液化及其震害的主要宏观特征。研究表明:场地液化是此次地震的主要震害之一,除地表破裂外,液化引发不均匀震陷,造成建筑物倾倒;液化激励地震动为0.15~0.50 g,主要集中于0.25 g以下;按修订的麦卡利烈度(modified mercalli intensity,MMI)表划分,液化点分布于VII度区,而按我国仪器烈度标准则液化点分布于VII~X度区域;液化宏观指数与以上两种烈度评定方法的关系在趋势上存在较大差异。

Seismic liquefaction is the main threat of engineering sites in earthquakes.In order to investigate the liquefaction characteristics of local earthquake damage caused by Turkey M_(w)7.8 earthquake on Feb.6,2023,the main macroscopic characteristics of site liquefaction and its damage in this earthquake are explained by applying the assessment methods of macroscopic liquefaction grade and macroscopic liquefaction index to analyze the image data of liquefaction damage investigation of this earthquake with Geographic Information System(GIS)technology.The research shows that site liquefaction is one of the main earthquake damage.Besides surface rupture,liquefaction causes uneven earthquake subsidence and leads to building collapse.Ground motion induced by liquefaction is 0.15-0.50 g,mainly concentrated below 0.25 g.According to the revised Modified Mercalli Intensity(MMI)table,the liquefaction point is located in the area of VII degree,while according to the national instrument intensity standard,the liquefaction point is located in the area of VII-X degree.The relationship between liquefaction macro-index and the two methods for intensity assessment is quite different in trend.