The influence of soils of selected sites of Addis Ababa on predicted earthquake ground motions

Abstract

One-dimensional nonlinear ground response analyses were conducted on selected sites of Addis Ababa. The sites were characterized based on the results of seismic and geotechnical surveys. Input motions were selected from the Pacific Earthquake Engineering Research Center (PEER) ground motion database. The results of the analyses show that the selected sites have a potential amplification significantly higher than the current seismic code specifications. In particular, the average PSA obtained at the ground surface is more than double the code values in the lower period range of up to 1.3 s. Considering that most buildings lie within this range, this calls for a revisiting of the code provisions for such sites of seismic prone areas in the region in general.