Document Type : Seismology and Engineering Seismology
Harbin Institute of Technology at Weihai
University of Illinois at Urbana-Champaign
Based on typical near-fault ground motions, relations between motion pulse amplitudes and periods are utilized to scale the difference of near-fault motions between rock and soil sites. Features of ground motion pseudo-velocity response spectra (PVS), normalized pseudo-velocity spectra (NPVS) and bi-normalized pseudo-velocity spectra (BNPVS) are examined by considering the influence of site conditions. Observations show that, the use of parameters PGV and Tp for the normalization of PVS is applicable. They can effectively reduce the scatter in the response spectra of long period range; ground motion pulse waveforms are affected by local site conditions, BNPVS values of soil sites are larger than those of rock sites at normalized period T/Tv less than about 0.7, while at relative periods larger than 0.7 the reverse is true; spectral peak value of BNPVS at rock sites is significantly higher than that of soil sites. Then, using simple pulses and available predictive relationships for near-fault motions, acceleration response spectra of the near-fault region are developed. The BNPVS are finally used to test the applicability of the established design spectra.