Sarpol-e Zahab Earthquake Damages to Roadway Bridges

A strong earthquake with moment magnitude of 7.3 occurred near the city of Sarpol-e Zahab in western Iran on November 12, 2017. The earthquake epicenter was located 10 km from Ezgeleh and 37 km from Sarpol-e Zahab. In this paper, damages to bridges located within 100 km from the epicenter are evaluated based on the field survey conducted one month after the earthquake. Bridges in the seismically affected cities and on primary roads leading to the city of Sarpol-e Zahab were inspected during the field survey. None of the inspected bridges were severely damaged, and they were all in service immediately after the earthquake.The observed damages were mostly minor in form of minor cracking across the decks, detachment of soil and abutments, and cracking of abutments. Some bridges were moderately damaged due to settlement and rotation of abutments which resulted in significant cracking of the deck. Damages occurred mainly in the abutments and to a lesser degree in the decks. Bridge bents in multi-span bridges did not experience any visible damage. This study indicates that concrete superstructures were more vulnerable than superstructures with steel girder. It also indicates that bridges with masonry abutments were more vulnerable than those with concrete abutments. Compared to single span bridges, the state of damage in multi-span bridges were more severe.