甘肃积石山M_(S)6.2地震高烈度区震害特征及机理分析

Characteristics and mechanism of seismic damage of residential buildings in high-intensity areas of Jishishan M_(S)6.2 earthquake

2023年12月18日甘肃积石山县发生M_(S)6.2地震,地震导致震中附近受灾严重,尤其以典型民居震害最为普遍和严重,对于研究典型民居震害机理具有警示意义。为研究典型民居的震害机理,通过震后第一时间的震害现场调查,获得典型民居破坏的第一手资料。针对破坏最为普遍的砖木房屋和砖混房屋作出宏观震害分析,并建立三维有限元数值模型,分析地震作用下两类房屋应力、应变的响应特性,揭示典型民居的地震破坏机理,并给出抗震建议。结果显示,地震作用下砖木房屋和砖混房屋主要以墙体破坏为主,在门窗部位及结构连接处均存在应力集中或应变增大现象,是造成民居震害的重要原因,加强对应力集中部位的抗震措施是减轻灾害的重要途径。研究结果对农村新建房和地震灾后重建具有指导意义。

On December 18,2023,the M_(S)6.2 earthquake in Jishishan County,Gansu Province,resulted in serious disasters near the epicenter,wherein the most extensive and severe damage occurred in typical residential buildings,revealing the importance of warning for studying the earthquake damage mechanism.The first-hand data were investigated immediately after the earthquake to examine the earthquake damage mechanism of typical dwellings.The macroscopic earthquake damage of commonly damaged brick-wood and brick-concrete houses was analyzed.A three-dimensional finite element numerical model was established to reveal the stress-strain response characteristics of the two kinds of houses under earthquake and the earthquake mechanism of typical dwellings.The anti-seismic recommendations were also provided.Results show that,under the action of an earthquake,the damage to brick-wood and brick-concrete houses is mainly concentrated in the walls.The damage to residential buildings is mainly attributed to the increase in stress concentration and strain on doors,windows,and structural connections.Therefore,strengthening earthquake-resistant measures in areas of high stress concentration is crucial to mitigating disasters.The results are beneficial to the construction of new rural houses and post-earthquake reconstruction.