ALBERT

Description:    This study examines distinctive features of ground motion parameters in northern Algeria. An initial computation of seismic hazard in terms of horizontal peak ground acceleration (PGA) and spectral acceleration (SA) at different periods, damped at 5%, is carried out for three different types of soils (rock, stiff soils and soft soils) for return periods of 100 and 475 years. In addition, uniform hazard spectra (UHS) are computed for these two return periods at several locations in the region. Then, the UHS computed for different soil types are proposed as a starting point to define elastic design spectra for building-code purposes. We have used the well-known Newmark-Hall approach. As proposed in the most recent International Building Codes, the SA (0.2 s) value is used to establish the spectral region for lower periods (region controlled by acceleration), whereas the SA (1.0 s) value is used to establish the spectral region for intermediate periods (region controlled by velocity). We also obtained important relations, dependent on site condition, between SA (0.2 s), SA (1.0 s) or SA max values, and the PGA, for both return periods of 100 and 475 years. Other relationships between PGA or SA max values have also been derived for return periods of 100 and 475 years, in this case independent of site condition. Content Type Journal Article Pages 1-13 DOI 10.1007/s00024-011-0333-z Authors M. Hamdache, Départment d’Études et Surveillance Sismique, Centre de Recherche en Astronomie, Astrophysique et de Géophysique, B.P. 63, Bouzaréah, 16340 Algiers, Algeria J. A. Peláez, Department of Physics, University of Jaén, Jaén, Spain A. Talbi, Départment d’Études et Surveillance Sismique, Centre de Recherche en Astronomie, Astrophysique et de Géophysique, B.P. 63, Bouzaréah, 16340 Algiers, Algeria M. Mobarki, Départment d’Études et Surveillance Sismique, Centre de Recherche en Astronomie, Astrophysique et de Géophysique, B.P. 63, Bouzaréah, 16340 Algiers, Algeria C. López Casado, Department of Theoretical Physics, University of Granada, Granada, Spain Journal Pure and Applied Geophysics Online ISSN 1420-9136 Print ISSN 0033-4553