Seismic performance of 8-Class Masonry School Building in Baghdad

Abstract

In 2017, a strong base excitation struck the Iraqi border near Halabja, which was classified as the latest earthquake in Iraq. Its reflection reached Baghdad city with an acceleration of (0.11 g). The objective of this paper is to study the results obtained by different seismic analysis methods, namely Time history analysis (THA), Response spectrum analysis (RSA), and Equivalent static analysis method (EQS), taking the building model adopted by the Ministry of Education in Iraq, designed first by masonry bearing walls system (M1), which was converted then into reinforced concrete moment resistance frames (M2) considering a reduction in stiffnesses and (M3) without reduction in stiffnesses. The ETABS V18 structural software program was adopted to perform FEM analyses. The results showed that the THA method gives lesser values concerning base shear for all models and minimum displacements in both directions. In contrast, the response analysis method is the safest and most conservative. It is noteworthy to mention that the equivalent static method gives closer results to the THA method. During analysis, it was found that applying factors of reduction in stiffness increased the results mentioned compared with those without considering it. Maximum base shear was noticed for building (M1). Due to the lack of proper records in Iraq, time histories were selected based on the ground motion records associated with earthquakes that occurred in Turkey, Iran, and Armenia to estimate the response spectrum.