张立宝, 傅磊 . 0: 地形效应对漾濞地震震害影响分析. 地震学报. doi: 10.11939/jass.20220085
引用本文: 张立宝, 傅磊 . 0: 地形效应对漾濞地震震害影响分析. 地震学报. doi: 10.11939/jass.20220085
LiBao ZHANG, Lei FU. 0: Analysis of the impact of Topographic effect on earthquake damage of Yangbi earthquake. Acta Seismologica Sinica. doi: 10.11939/jass.20220085
Citation: LiBao ZHANG, Lei FU. 0: Analysis of the impact of Topographic effect on earthquake damage of Yangbi earthquake. Acta Seismologica Sinica. doi: 10.11939/jass.20220085

地形效应对漾濞地震震害影响分析

Analysis of the impact of Topographic effect on earthquake damage of Yangbi earthquake

  • 摘要: 本文对2021年5月21日漾濞MS6.4地震微观震中绣岭村进行了震害调查。以流动观测地形台阵观测资料为基础,分析了地形效应对地震动特性的影响,分析表明若地震波垂直山脉走向入射,陡坡会放大地震波的高频部分,不同高程傅里叶幅值谱沿山脉走向和垂向的低频部分存在明显差异。同时,利用谱衰减法计算高频衰减参数的场地分量(k0),分析k0水平分量、竖向分量、水平分量/竖向分量分别与台站高程、场地软弱程度、卓越频率的关系,分析结果表明,在近距离范围内(<30 km),微震、小震的水平k0不受卓越频率和高程变化的影响,而竖向k0对卓越频率和高程变化敏感;场地越软,水平k0越大,而竖向k0变化规律不明显。

     

    Abstract: This paper conducted a damage investigation on the micro epicenter of the Yangbi Ms6.4 earthquake on May 21, 2021. Based on the observation data of mobile observation topographic array, the influence of topographic effect on ground motion characteristics is analyzed. It is found that if the seismic wave is incident perpendicular to the mountain trend, the steep slope will amplify the high-frequency part of the seismic wave, and there are obvious differences in the low-frequency part of Fourier amplitude spectrum along the mountain trend and vertical at different elevations. The site component(k0) of high-frequency attenuation parameters is calculated by spectral attenuation method, then the relationship between the horizontal component of k0, the vertical component of k0, the ratio of horizontal to vertical component of k0 and station elevation, site weakness and dominant frequency is analyzed respectively. The results show that for micro and small earthquakes within a near distance (<30 km), the horizontal component of k0 is not affected by the dominant frequency and elevation changes, but to which the vertical component of k0 is sensitive to; The soft the site, the larger the horizontal component of k0, while the variation of the vertical component of k0 is not obvious.

     

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