ANALYSIS OF THE 2003, ZEMMOURI, ALGERIA EARTHQUAKE, FROM STRONG GROUND MOTION DATA

On 21 May 2003, a major earthquake with magnitude 6.8 MW (6.9 MS) struck the environs of Algiers, the capital of Algeria, causing important damages in different provinces in the Center-North of the country. This work is related to the results obtained in the processing of the accelerogram records of the 21 May 2003 Zemmouri (Algeria) earthquake. From the accelerograms, several interesting parameters in seismic engineering studies have been obtained such as PGA, PGV and PGD, duration, arms , and Arias and Housner intensities. Hodograms, pseudo acceleration spectra and H/V spectral ratios from earthquake data have been computed as well. The strong ground motion is in agreement with the rupture propagation, i.e., an asymmetric bilateral rupture. A strong directivity is obtained from the processing of the records, also inferred, for example, from the isoseismal map. A strong site effect appears in certain accelerograph stations, due to their location on Quaternary alluvial deposits. In other records, surface waves generated at the edges of the sedimentary basin can be seen. Finally, pseudo acceleration spectra, computed uniform hazard spectra and design elastic response spectra are compared and discussed at these locations.