摘要
基于确定性物理模型的全过程地震动模拟是现代地震工程的重要发展方向.然而受限于合理震源模型和计算资源需求,目前模拟的有效频率还多处于低频范围,难以满足工程结构敏感频带(5~10 Hz或更高)需求.本文即借助运动学混合震源模型能激发宽频地震波和谱元法空间高精度及计算收敛快的优势,首先将确定性的凹凸体震源模型与GP14.3随机震源模型结合得到有限断层运动学混合震源模型,进而将上述混合震源模型开发到SPECFEM 3D谱元法开源代码中,实现了基于谱元法和运动学混合震源模型的全过程宽频带地震动模拟.将方法首先应用于一维波速结构模型0~10 Hz地震动模拟,通过与频率波数域(FK)方法结果进行比较,验证了方法的精度;进而应用于2021年5月21日云南漾濞6.4级地震0.1~5 Hz地震动模拟,通过与4个台站的时程记录和相应反应谱的比较,以及与NGA-West2地震动衰减方程在频率0.1~5 Hz的反应谱的比较,检验了方法的适用性;最后给出了漾濞地区的地震动峰值加速度(PGA)和峰值速度(PGV)云图,分析了漾濞地震下近场强地面运动的空间分布特征.结果显示,震中PGA接近400 cm·s-2,PGV达到45 cm·s^(-1),烈度达到Ⅸ度,且受局部地形起伏影响,大理以及洱海西侧位置出现高烈度异常区.
The overall process ground motion simulation based on deterministic physical model is an important development direction of modern earthquake engineering. However, due to the limitations of appropriate fault source model and computing resource requirements, the effective frequency of simulation is mostly in the low frequency range, which is difficult to meet the needs of engineering structure sensitive frequency band(5~10 Hz or higher). In this paper, with the combination of kinematic hybrid source model can stimulate the broadband seismic wave and the spectral element method has the advantages of high spatial accuracy and fast convergence, the deterministic asperity source model is combined with GP14.3 stochastic source model to obtain the finite fault kinematic hybrid source model, and then the hybrid source model is developed into SPECFEM 3D code. The overall process broadband ground motion simulation based on spectral element method and kinematic hybrid source model is realized. Firstly, the work is applied to 0~10 Hz ground motion simulation of one-dimensional wave velocity structure model. The accuracy of the proposed method is verified by comparing with the frequency wave-number domain(FK) method proposed by the authors. Then, the Yangbi MS6.4 earthquake in Yunnan province on May 21, 2021 is simulated with 0.1~5 Hz ground motion. The applicability of the method is verified by comparing with the time-history and response spectrum recorded by four stations and compared with the response spectrum of the NGA-West2 ground motion attenuation equation at frequencies of 0.1~5 Hz. Finally, the Yangbi area is simulated with peak acceleration and velocity distribution and the spatial distribution characteristics of near field intensity ground motion under the Yangbi earthquake are analyzed. The results show that the peak acceleration and peak velocity of the epicentral extreme earthquake area are closed to 400 cm·s-2and 45 cm·s^(-1), the maximum intensity of the extreme earthquake area could reach Ⅸ and affected
作者
巴振宁
赵靖轩
张郁山
梁建文
张玉洁
BA ZhenNing;ZHAO JingXuan;ZHANG YuShan;LIANG JianWen;ZHANG YuJie(Key Laboratory of Earthquake Engineering Simulation and Seismic Resilience of China Earthquake Administration(Tianjin University),Tianjin 300350,China;Department of Civil Engineering,Tianjin University,Tianjin 300350,China;China Earthquake Disaster Prevention Centre,Beijing 100029,China)
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第3期1125-1138,共14页
Chinese Journal of Geophysics
基金
国家自然科学基金资助项目(52178495)
中南大学前沿交叉研究项目(2023QYJC006)共同资助。
关键词
宽频地震动
运动学混合震源模型
确定性物理模型地震动模拟
谱元法
Broadband ground motion
Hybrid kinematic source model
Deterministic physical ground motion simulation
Spectral element method
