VULNERABILITY ASSESSMENT OF RESIDENTIAL BUILDINGS IN JEDDAH: A METHODOLOGICAL PROPOSAL

Abstract

The City of Jeddah in Saudi Arabia is expanding rapidly, in terms of new buildings and
increasing population. The rapid urbanization leads to higher risk from seismic events; even in areas of
moderate seismicity such as this city. The present study addresses the rapid evaluation of a large number of
buildings in Jeddah involving steps to determine hazard, assessing building stock, and computing vulnerability
with a scoring method from FEMA 155. Two districts were selected for investigation based on a cluster
analysis applied to population and building data from the local municipality. One selected district was a
contemporary developed urbanized area, and the other was a more traditional area. Such selection offered the
possibility to compare vulnerability of buildings built according to different seismic codes and to make
assumptions about the rest of the city based on typical structures of districts. The basic structural score was
determined considering the building structure and moderate seismicity of the region using score modifiers, e.g.
vertical irregularity score modifier; soil score modifier assuming sabkahs. The results of the investigation
reveal a different level of vulnerability and areas where intervention is needed. The method can be applied for
further analysis of the city.