Abstract
This article deals with the liquid seismic effect owing to excitation of lateral base. When the rectangular reservoir contained the contained liquid vibrates, the liquid exerts the hydrodynamic pressure on the reservoir walls and the reservoir bottom. First the theoretical background of the fluid seismic effect on the solid domain of the rectangular reservoir is described in the paper. Thereafter, the rectangular fluid filing excited by the earth surface movement was calculated. The analysis of the liquid effect was situated for locality near Nador city at Morocco and respects of Eurocode recommendations.