Integrate the Methods of Linear Full Resonance with Quarter-Wavelength into Strong Motion Synthesis

The local site condition plays a crucial role in the study of strong ground motion, and much effort has been expended. The most common theoretical methods are linear full resonance (FR), quarter-wavelength (QWL), equivalent linear and nonlinear. We compare the site response from these two methods and the combination of them for the mainshock of the 2016 Kumamoto earthquake. The surface-borehole recordings at a far-field station FKOH01 and a near-fault station KMMH03 are selected as benchmark. Horizontal ground motions at these two borehole stations are simulated. The site effect is evaluated by three methods of FR, QWL and the combination QWL × FR. At FKOH01, PGAs from QWL × FR are larger than those from QWL and FR; at KMMH03, PGAs from QWL are larger than those from QWL × FR, and the latter are close to those from FR. A similar trend is observed in the comparison of response spectra. Compared with the records, QWL × FR can be adopted to evaluate the site response.