Updated Seismic Input for Next Generation of the Egyptian Building Code

Abstract

Egypt is prone to earthquakes of moderate and strong size from inland and distant seismogenic sources. The seismicity and seismic hazard studies have indicated that the country face moderate seismic hazard. Current practice in the Egyptian building code considers seismic load using seismic input from old seismic zonation map that go back to the late 90’s. Although, this map was developed using a traditional seismic hazard approach, the seismic design strategy, as well as the building code and its update; rely upon it. Also, despite the several developments in the understanding of seismicity, crustal deformation and earthquake mechanics in Egypt that have been achieved in the last two decades, also the presence of theoretical and practical developments, the current seismic load computation of the code is still dangerously adopt and recommend this map. Therefore, the current practice needs an urgent revisit and update. The main aim of this work is to estimate the ground motion parameters in the form of accessible digital maps or databases (e.g. Peak Ground Acceleration, velocity, displacement, response spectra, and time histories) that can be used as input for the next generation of the Egyptian Building code. Physics-based seismic hazard maps and/input are computed where uncertainties are properly evaluated and communicated to the end users. Also, the newly developed maps or input provide a wide range of ground motion parameters in the form of digital databases, not only limited to peak ground motion values, but comprise also excitation records, response spectra or any other ground motion parameter relevant to seismic engineering. The main delivers of this work will be archived and presented using GIS tool that covers whole Egypt with several thousands of sites (nodes), at each node/site. A geospatial database of computed time histories (seismograms and accelerograms) due to all possible seismic sources that can affect those sites are provided. In addition, at each site a representative response spectrum that envelopes all possible ground motion parameters with different percentiles are given.