Site effect influence on the seismic vulnerability of unreinforced masonry buildings in low to moderate seismic urban areas in Algeria

PurposeThis paper aims to develop preliminary damage scenarios for unreinforced masonry buildings located in low to moderate seismic hazard areas in Algeria, taking into account the specific site effects.Design/methodology/approachThree soil types were considered in this analysis according to the definition of the Algerian seismic code (RPA99/2003). Peak ground acceleration values were assigned to each soil type issued from a probabilistic seismic hazard analysis (PSHA). To highlight the effect of soil conditions on the seismic vulnerability analysis of masonry buildings, a site vulnerability increment is carried out, and the macroseismic Risk-UE method has been adopted and applied by developing two main seismic scenarios according to both return periods of the PSHA, 100 and 475 years, respectively.FindingsBased on the preliminary results of rock site condition, it can be outlined that the significant damage obtained for different earthquake scenarios discovered a substantial worldwide seismic risk to the building stock of the study area. Once the site effect is integrated into the analysis, more high values of vulnerability indexes and expected damages are obtained. Moreover, it can be concluded that soft soil (S3) is a little bit more influential than stiff soil (S2) on the final vulnerability index compared to (S1). However, the difference between the soil effect S2 and S3 on the vulnerability index can be neglected.Research limitations/implicationsResearchers are encouraged to test the mechanical approaches for more detailed outcomes of a specific building analysis.Practical implicationsThis research proves to the Algerian decision-makers that due to the site effects and the vulnerability of the masonry buildings, an urgent intervention program is required even for existing buildings located in low to moderate seismic hazard areas.Originality/valueSeveral seismic vulnerability types of research have been conducted in Algeria for the unreinforced masonry buildings in moderate to high seismic areas in which generally the soil effect is neglected. In this context, this research paper proves that due to the site effects and the vulnerability of the masonry buildings, special attention is required even for existing buildings located in low to moderate seismic hazard areas. With this conclusion, the requirement of taking into account the soli effect in the high seismic areas is even more pronounced and should be conducted.