Seismic Scenario of Algiers City: Case Study of Strengthened Masonry Buildings

Abstract

Strengthened masonry buildings are one of the most common types of old structure usually located in the ancient Algerian urban nuclei. The present study focused on common strengthened masonry buildings. Feedback from seismic experiments has shown that their dynamic behavior is generally nonlinear and highly vulnerable to earthquakes. Also, in order to predict the rate of damage that could occur to this type of structure in the event of earthquakes, empirical fragility curves based on a probabilistic method have been developed. In this study, seismic fragility analysis has been performed using the vulnerability index and the average damage rate. The vulnerability index will belong to one of three vulnerability classes determined by nonlinear dynamic analysis. The average damage is obtained using a deterministic method taking into account the vulnerability index and the seismic intensity. The fragility curves, which give the probability of achieving or exceeding a certain damage level for the three classes of vulnerability considered, have been compared to different studies that developed similar analyses. A seismic scenario was performed using a geographic information system and applied to strengthened masonry buildings located in Algiers city, which was built before the first Algerian seismic regulations of 1981.