【摘要】 利用美国太平洋地震工程研究中心NGA数据库,分析了滤波低频截止周期(Tc)对位移反应谱的影响。选择较小的Tc将严重抑制长周期位移反应谱幅值。本文选用可靠使用周期不小于10 s的强地面运动加速度记录,研究了位移反应谱的长周期特性。结果表明,位移反应谱峰点周期是长周期地震反应谱的关键控制参数,受场地条件和震级的影响相对较小,但与震中距基本呈线性增长关系,而动力放大系数最大值波动范围较小,设计中可视为常数。建议在现行抗震设计规范谱的基础上,在速度控制段与位移控制段之间增加一个过渡段,以体现位移反应谱的有峰特征,并给出了控制参数的建议值。更多还原

【Abstract】 The effect of the long-period filter cut-off,Tc,on spectral displacements is analysed using the NGA database of the Pacific Earthquake Engineering Research Center.Long-period spectral displacements would be suppressed badly,if a short Tc is chosen.Strong ground motion accelerograms with reliable period up to at least 10s are selected to investigate the characteristics of displacement response spectra at long periods.The results indicate that the period,in which the spectral displacement culminates,is a significant parameter to control long-period spectral ordinates.This parameter can’t be affected obviously by site condition and magnitude,but greatly depends on epicentral distance with linear relation.The maximum amplification factor of displacement spectrum fluctuates slightly,and can be treated as a constant.A transition region is suggested to insert between velocity-sensitive region and displacement-sensitive region to fit for displacement spectrum,and the values of some parameters are proposed in this paper.更多还原