用数字地震台网小震数据估计东南沿海地区地震动
发布时间：2018-10-16 09:58
【摘要】：地震动衰减关系是工程地震研究的核心,简化了地震的震源、地震波的传播途径以及局部场地条件三方面因素对地震动特性的影响,可以为重大工程结构抗震设计工作提供合理的抗震设防参数。目前,在美国西部和日本等强震记录丰富的国家和地区,主要利用强地震动观测数据统计回归的方法建立经验性衰减关系。然而,我国大陆强震记录相对较少,如何建立强地震动衰减关系一直是工程地震领域的研究热点。另一方面,“十一五”之后,随着中国大陆数字地震观测技术和地震观测能力的不断发展进步,地震监测能力得到了大幅度提高,国家及区域宽频带数字地震台网都积累了大量的数字地震波形资料。本文借助宽频带数字地震监测台网小震记录,估计东南沿海地区地震动。论文主要完成了以下工作:1.在东南沿海地区(北纬22°-29°,东经109°-120°),收集到广东和福建区域数字地震观测台网和国家数字测震台网数据备份中心在1999年到2013年间记录到的72次小震(Mw=3.5-4.5、震源深度≤30km)的1274条记录。2.将收集到的测震数据按照地震震中位置的不同划分为海域、陆域和全部数据三组,以傅里叶幅值谱的包络线为目标曲线,借助微遗传算法,反演5个区域震源和地壳介质参数(应力降Δσ、品质因子参数Q0和η、几何衰减参数R1和R2),三组数据反演结果差别不大。3.在建立强地震动衰减关系的过程中,将近地表高频截止项用Kappa滤波器表达,分别采用Original Kappa和Fixed-Kappa两种方法计算测震数据的Kappa值。讨论两种Kappa值与矩震级、震源深度和震中距的关系。研究表明,Kappa值与震级大小和震源深度之间没有相关性,与距离相关。4.将反演的区域参数和两个Kappa值分别代入计算程序,建立相应的强地震动衰减关系。与东南沿海地区有限的强震观测数据比较,验证本文衰减关系的可靠性。5.结合本文反演的区域震源与地壳介质参数,以及用测震数据得到的Kappa值,借助有限断层混合震源模型,合成了九龙江断裂6.0级地震中5个试算点的地震动。与经验性给出区域参数得到的试算点反应谱比较,本文结果偏高,原因是反演参数值比经验性给出的数值大;与本文建立的衰减关系得到的试算点反应谱比较,短周期接近,有限断层混合震源模型结果表现出上盘效应和方向性效应。
[Abstract]:The attenuation relation of ground motion is the core of engineering seismic research. It simplifies the influence of earthquake source, propagation path of seismic wave and local site conditions on the characteristics of earthquake motion. It can provide reasonable seismic fortification parameters for seismic design of major engineering structures. At present, in countries and regions with abundant records of strong earthquakes in the western United States and Japan, the empirical attenuation relationship is established by means of statistical regression method of strong ground motion observation data. However, there are relatively few records of strong earthquakes in the mainland of China. How to establish the attenuation relationship of strong ground motion has been a hot topic in the field of engineering earthquake. On the other hand, after the 11th Five-Year Plan, with the continuous development and progress of digital seismic observation technology and seismic observation capability in the mainland of China, the ability of seismic monitoring has been greatly improved. National and regional broadband digital seismic networks have accumulated a large number of digital seismic waveform data. In this paper, the ground motion in southeast coastal area is estimated by using the small earthquake records of broadband digital seismic monitoring network. The main work of this paper is as follows: 1. In the southeast coastal area (latitude 22 掳-29 掳N and longitude 109 掳-120 掳E), 1274 records of 72 small earthquakes (Mw=3.5-4.5, focal depth 鈮，
本文编号：2273997
[Abstract]:The attenuation relation of ground motion is the core of engineering seismic research. It simplifies the influence of earthquake source, propagation path of seismic wave and local site conditions on the characteristics of earthquake motion. It can provide reasonable seismic fortification parameters for seismic design of major engineering structures. At present, in countries and regions with abundant records of strong earthquakes in the western United States and Japan, the empirical attenuation relationship is established by means of statistical regression method of strong ground motion observation data. However, there are relatively few records of strong earthquakes in the mainland of China. How to establish the attenuation relationship of strong ground motion has been a hot topic in the field of engineering earthquake. On the other hand, after the 11th Five-Year Plan, with the continuous development and progress of digital seismic observation technology and seismic observation capability in the mainland of China, the ability of seismic monitoring has been greatly improved. National and regional broadband digital seismic networks have accumulated a large number of digital seismic waveform data. In this paper, the ground motion in southeast coastal area is estimated by using the small earthquake records of broadband digital seismic monitoring network. The main work of this paper is as follows: 1. In the southeast coastal area (latitude 22 掳-29 掳N and longitude 109 掳-120 掳E), 1274 records of 72 small earthquakes (Mw=3.5-4.5, focal depth 鈮，
本文编号：2273997
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