基于四区域椭圆模型的汶川8.0地震加速度峰值衰减关系拟合

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振动与冲击 ›› 2010, Vol. 29 ›› Issue (5) : 136-140.

论文

基于四区域椭圆模型的汶川8.0地震加速度峰值衰减关系拟合

杨帆1;罗奇峰2

作者信息 +

wenchuan 8.0 Magnitude earthquake Acceleration peak Attenuation Curve using Four-area elliptical model

yangfan1;luoqifeng2

Author information +

文章历史 +

摘要

利用加速度记录直接拟合衰减关系时，现行几乎所有文献都采用圆模型，以震中距或震源距为观测点坐标位置的唯一统计量。对于长断层的大震而言，等震线的圆模型假设和实际等震线图存在严重的偏差，加速度峰值在沿断层方向的长轴和垂直于断层方向的短轴衰减关系差异非常明显。本文提出的加速度衰减关系的四区域椭圆模型，按断层破裂方向的长轴和过断层为中心垂直于长轴的短轴将地震记录观测点位置分为四个区域，以烈度等值线为参考，给出了四个区域内各自的加速度峰值等值线的椭圆近似曲线。并在此基础上得出了汶川8.0级地震加速度峰值在两个长半轴和两个短半轴方向上的衰减关系，和圆模型相比，本文模型在精度上更加可靠，且能够反映断层破裂方向效应和上下盘效应，具有较强的工程应用价值。

Abstract

At present, equal-distance circle model is generally used for directly fitting acceleration peak attenuation curve. epicentral distance or focal distance is only coordinate statistical parameter of seismic station. For large earthquake with a long faults, the isoseismic curve of equal-distance exist serious deviation from realistic isoseismic curve. There is enormous variations for acceleration peak attenuation curve to longest axis and to shortest axis. Four-area elliptical model in this paper devided seismic station into four area according to longest axis and shortest axis. Every elliptical Acceleration isoseismic in four area is respectively figured out by the way of interpolation referred to seismic intensity isoseismic curve. On the basis of this, Wenchuan earthquake acceleration peak attenuation curve be obtained in two longest semiaxis direction and two shortest semiaxis direction. Comparing results of Wenchuan 8.0 magnitude earthquake acceleration peak Attenuation Curve using circle model and Four-area elliptical model, the latter is more Close to the real situation and get more useful results including reflected hanging and foot wall effect and direction effect of earthquake.

导出引用

杨帆;罗奇峰 . 基于四区域椭圆模型的汶川8.0地震加速度峰值衰减关系拟合[J]. 振动与冲击, 2010, 29(5): 136-140

yangfan;luoqifeng. wenchuan 8.0 Magnitude earthquake Acceleration peak Attenuation Curve using Four-area elliptical model[J]. Journal of Vibration and Shock, 2010, 29(5): 136-140