Ground motion analysis of the 2003 Zemmouri, Algeria,earthquake

摘要

A 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.The contribution of this event in the seismic hazard assessment in the central part of Algeria was examined. The result in terms of PGA shows seismic hazard values 40% higher on average than previously reported, especially in the south-west part of the Mitidja basin. This work is related to the results obtained in the processing of the accelerogram records of this 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. Besides,a clear site effect appears in certain 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,bstract