HVSR方法用于地震作用下场地效应分析的适用性研究

以美国Garner Valley Downhole Array（GVDA）竖向观测台阵的强震观测记录为基础，利用水平与竖向谱比（Horizontal-to-Vertical Spectral Ratio， HVSR）方法与传统谱比方法研究了多次地震作用下竖向台阵场地的波动传播规律，探讨了该场地HVSR曲线与传递函数（Transfer Function， TF）曲线的差异，综合利用频域求解一维层状场地P、SV波入射情况下场地响应的土层地震反应分析方法和合成理论地震图的波数积分法解释了二者差异可能的原因，在此基础上研究了HVSR方法应用于地震作用下场地效应分析的适用性.研究结论表明：竖向地震动场地效应是HVSR与传递函数产生差异的主要原因，竖向地震动场地效应主要是由竖向地震动中的P波成分引起的.在场地竖向放大可以忽略的频段范围内，HVSR可以作为传递函数研究地震作用下的场地效应.

Applicability of HVSR in analysis of site-effects caused by earthquakes

This work is based on strong ground motion records from the Garner Valley Downhole Array (GVDA) in Southern California. The Horizontal-to-Vertical Spectral Ratio (HVSR) method and traditional spectral ratio method have been used to study propagation characteristics. The discrepancy between HVSRs and transfer functions has been explored and interpreted through seismic response analysis method which can deal with site response under the excitation of P or SV waves in frequency domain and wave number integral method used for synthetic seismogram.After that, the applicability of HVSR in analysis of site-effects caused by earthquakes has been discussed. The results show that the discrepancy between HVSRs and transfer functions is mainly caused by the significant site response of the vertical component due to incident P-waves from the bedrock through the soil column. For the frequency range in which the vertical site response can be completely ignored, the HVSRs can be used as transfer functions to study site-effects produced by earthquakes.