地震工程学报2017，Vol.39Issue(1)：160-167,8.DOI:10.3969/j.issn.1000-0844.2017.01.0160
P波入射下断层参数对地表地震动的影响
Influence of Fault Parameters on Ground Motion under Incident P Waves
摘要
Abstract
In this study,a numerical solution for a 2-D fault site model under incident P waves using the explicit finite element method combined with transmission of artificial boundary condi-tion was derived.The distribution rules of peak ground acceleration (PGA)and the spectrum characteristics influenced by fault characteristics such as width and shear wave velocity of the fault and the incidence angle of the seismic waves were discussed.Numerical simulations shown that transform SV waves developed in the low velocity fault zone (LVFZ)when it struck by external incident P waves,and many trapped waves obviously developed in it.This result implied that the external incident seismic radiation congregated in the LVFZ,and the agglomeration effect increased with the increased width and decreased shear wave velocity of the LVFZ.Vertical LVFZs blocked the spread of oblique incident P waves,and the isolation effect decreased with the increased incidence angle of P waves.The seismic response of a variety of LVFZ models withdifferent width and shear wave velocity struck by external vertically incident P waves was deter-mined,and the results implied that the ground motion amplification characteristics in the near fault zone site are frequency dependent.The higher frequency components of ground seismic waves are obviously amplified by LVFZs with narrower widths and higher shear wave velocities, while the lower frequency components of ground seismic waves are obviously amplified by LVFZs with wider widths and lower shear wave velocities.In other words,the site amplification coeffi-cient is frequency dependent,such that the widening the width or decreasing the shear wave velocity of fault fracture zone,the predominant frequency of a larger site amplification coefficient is becoming lower.关键词
非发震断层场地/断层破碎带/断层陷波/集聚效应/频率相关/隔震效应Key words
non-causative fault site/fault fracture zone/trapped wave/agglomeration effect/frequency dependent/isolation effect分类
天文与地球科学引用本文复制引用
刘必灯,于淼,王伟,周正华,李小军..P波入射下断层参数对地表地震动的影响[J].地震工程学报,2017,39(1):160-167,8.基金项目
国家自然科学基金(51208107,51208234,51308118) （51208107,51208234,51308118）
中央高校基本科研业务费专项(ZY20120103) （ZY20120103）
