摘要
2025年1月7日的西藏定日6.8级地震造成了大量建筑倒塌破坏和重大人员伤亡。为分析此次地震震害原因,该文采用国家烈度速报与预警工程台网获取的35组强震动记录,分析了近场地震动的幅频特性与传播衰减规律。通过与中国西南地区地震动预测模型(ZYLW22模型)进行对比分析发现:地震的近场地震动参数(包括加速度峰值和反应谱值)实测值略低于模型的预测值,而远场观测数据则呈现高于模型预测值的特征。研究表明,本次地震的高烈度区地震动具有显著的1.0~3.0 Hz高频能量优势特征。定日地震震中处于农牧区,震区建筑结构以自建低矮石木/土坯和框架民居结构为主,结构整体性较差、自振周期接近地震动特征周期,导致大量民居结构倒塌破坏,这是本次地震致灾的关键因素。此外,定日地震近断层地震动还表现出震源破裂方向性效应特性。
The M_(S)6.8 Dingri earthquake in Xizang on January 7,2025,caused extensive building collapses and significant casualties.To investigate the causes of seismic damage,this study analyzed the amplitude-frequency characteristics and propagation attenuation characteristics of near-field ground motions using 35 sets of strong motion records obtained from the National Intensity Rapid Reporting and Early Warning Network.Through comparative analysis with the seismic ground motion prediction model(ZYLW22 model)for southwestern China,it was found that the measured values of near-field ground motion parameters(including peak ground acceleration and response spectra)were found to be slightly lower than the model predictions,while far-field observations exhibited higher values than predicted.Spectral analysis revealed a pronounced high-frequency energy dominance in the 1.0~3.0 Hz range within high-intensity zones of the earthquake.The epicentral region of the Dingri earthquake lies in a pastoral-agricultural area,where local buildings predominantly consist of self-built low-rise stone/wood or adobe structures and simple frame residential buildings.The earthquake disaster may be attributed to the poor structural integrity of these buildings,whose natural vibration periods closely match the predominant periods of ground motions,resulting in widespread structural failures.Additionally,the near-fault ground motions of the Dingri earthquake also exhibited source rupture directivity effects.
作者
王江
卢建旗
林德昕
钱亮
李津丞
任智豪
马强
WANG Jiang;LU Jianqi;LIN Dexin;QIAN Liang;LI Jincheng;REN Zhihao;MA Qiang(Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;Key Laboratory of Earthquake Disaster Mitigation,Ministry of Emergency Management,Harbin 150080,China)
出处
《地震工程与工程振动》
北大核心
2025年第5期1-8,共8页
Earthquake Engineering and Engineering Dynamics
基金
中国地震局工程力学研究所基本科研业务费专项资助项目(2025C01)
国家自然科学基金项目(42404078)。
