The site response analyzes provide an idea of the behavior of the soil against strong ground motions, involving a large number of variables that determine the non-linear behavior of the soil. Due to the complexity of these analyzes, in practice the effects of nonlinear soil behavior are incorporated factors that modify the seismic response of a response spectrum in rock (linear behavior). In this study, nonlinear site response analysis has been performed for 50 soil profiles in an attempt for covering a wide range of shear wave velocity profiles using the software DEEPSOIL V.7. For this purpose, 06 seismic records have been spectrally adjusted to uniform hazard spectrum of 475, 1000 and 2475 years of return period. Subsequently, a comparison of the results obtained from the site response analysis with the parameters stipulated in the Peruvian Seismic Design Code E.030 (2018) was made, in...

The site response analyzes provide an idea of the behavior of the soil against strong ground motions, involving a large number of variables that determine the non-linear behavior of the soil. Due to the complexity of these analyzes, in practice the effects of nonlinear soil behavior are incorporated factors that modify the seismic response of a response spectrum in rock (linear behavior). In this study, nonlinear site response analysis has been performed for 50 soil profiles in an attempt for covering a wide range of shear wave velocity profiles using the software DEEPSOIL V.7. For this purpose, 06 seismic records have been spectrally adjusted to uniform hazard spectrum of 475, 1000 and 2475 years of return period. Subsequently, a comparison of the results obtained from the site response analysis with the parameters stipulated in the Peruvian Seismic Design Code E.030 (2018) was made, in...

Effects of local site, propagation path and source in ground motion records observed in Lima, Peru, were separated by the spectral inversion method proposed by Iwata and Irikura (1986 [1], 1988 [2]) to examine the relation between local subsurface conditions and local site amplifications in a frequency range from 0.5 to 20 Hz. S-wave portions of accelerograms in horizontal components observed at 5 stations for 11 events along the Pacific coast of Lima city, Peru, were analyzed. The Q factor was obtained from our inversion results as frequency dependent function QS( f) = 80.4 f 0.63. In terms of local site effects, stations located on alluvial gravel deposits were likely to suffer amplification at frequencies larger than 4 Hz, while one station (CAL site) located on soft soil sediment has different behavior of amplification. We also compared our results with 1-D theoretical computation, o...

We investigated the broadband frequency (0.05-30 Hz) radiation characteristics of the August 15, 2007, Mw8.0 Pisco, Peru, earthquake by simulating the near-source strong ground motion recordings in Parcona city (PCN) and Lima city (NNA). A source model of this earthquake obtained from long-period teleseismic waveforms and InSar data shows two separate asperities, which is consistent with the observation of two distinct episodes of strong shaking in strong motion recordings. We constructed a source model that reproduces near-source records at low frequency (0.05-0.8 Hz) as well as high frequency (0.8-30 Hz) bands. Our results show that the aforementioned teleseismic source model is appropriate for simulating near-source low frequency ground motion. Our modeling of the PCN record in the broad-frequency band indicates that a very strong high frequency radiation event likely occurred near th...

Microtremor exploration was performed around seismic recording stations at five sites in Lima city, Peru in order to know the site amplification at these sites. The Spatial Autocorrelation (SPAC) method was applied to determine the observed phase velocity dispersion curve, which was subsequently inverted in order to estimate the 1-D S-wave velocity structure. From these results, the theoretical amplification factor was calculated to evaluate the site effect at each site. S-wave velocity profiles at alluvial gravel sites have S-wave velocities ranging from ∼500 to ∼1500 m/s which gradually increase with depth, while Vs profiles at sites located on fine alluvial material such as sand and silt have Swave velocities that vary between ∼200 and ∼500 m/s. The site responses of all Vs profiles show relatively high amplification levels at frequencies larger than 3 Hz. The average transfer...