post-earthquake reconnaissance of sarpol-e zahab concrete buildings after 6.4 magnitude aftershock

In the 7.3 magnitude earthquake of november 12, 2017, the concrete buildings in sarpol-e zahab were severely damaged and even collapsed. the concrete building systems can be divided into three categories: moment resisting frames, shear walls and dual systems. moment resisting frame systems are very popular because of their low cost and easeof construction. in this type of structural system, both gravity and lateral forces are supported by beams and columns. shear wall systems in concrete buildings are used to provide stiffness and strength of the buildings against lateralforces such as earthquakes. such structures are usually stiff and they behave well specially if they are combined with moment resisting frames. ductility of the concrete elements depends highly on reinforcement detailing. our observations show that insufficient bending details in stirrups, inadequate overlap length for longitudinal bars and deficient curing of the concrete are the main reasons of damages in such buildings.