摘要
本文根据地震动时程强度变化分为上升、持续平稳、下降三个阶段的特点,首先从单个记录入手,分别研究确定了不同震级、距离、场地记录的包络参数,然后将与全部记录对应的包络参数用统计方法拟合它们随震级、距离、场地条件变化的衰减关系。结果表明,时程强度包络线的上升时间t_1与P波、S波传播至观测点的到时差相关,随R的增大而加长;下降段则随M、R增大而减缓;中间平稳持续段长度T_s随M、R增大呈增长趋势,但在近场区首次发现T_s具有大震饱和特性。包络函数还与场地条件有关,它将常规的强振持时概括其中,更全面反映了时程强度包络变化的特征。
Based on the strong ground motion records,the envelope function f(t) of acceleration time history is scaled in terms of magnitude,distance,and site condition.Here f(t) is composed with arising(t<t1),stationary(t=t2-t1),and descending(t>t2) parts and all the model parameters are expressed as the function of M and R.The results show that the arising time t1 is similar to the difference of time arrivals of P and S waves,that the descending rate becomes smaller with the increase of M and R,and that Ts=t2-t1 for the stationary part is proportional to M and R except for the epicentral region where T saturates just like the acceleration of ground motion.
出处
《地震工程与工程振动》
CSCD
北大核心
1991年第1期1-12,共12页
Earthquake Engineering and Engineering Dynamics
