Estimation of site response using the H/V method. Applicability and limits of this technique on Garner Valley Downhole Array dataset (California)

摘要

The possibilities and limits of the use of the Nakamura’s method to estimate site responseare tested by comparing data collected at the Garner Valley Downhole Array and theoreticalanalysis of the polarisation of Rayleigh waves. We show that in the GVDA case the H/V peak frequenciesand values are not related to the polarisation curve of the fundamental mode of Rayleighwaves. The comparison with the transfer functions obtained with the accelerometers in the boreholesin GVDA could suggest that they may be related to the amplification of upgoing S wavescreated by noise or higher modes polarisation. In this case, the amplification level and the resonancefrequency found by the Nakamura’s method depend on the penetration’s depth of the wavescreated by the noise.