Document Type : Structural Earthquake Engineering
Risk and Reliability Engineering, San Jose
International Centre for Geohazards
Engineering Geology Department, Geological Survey of Iran
At 5:26 am local time, Friday, December 26, 2003, an earthquake with moment magnitude 6.5 hit the city of Bam in southeast Iran. The earthquake caused more than 26,000 deaths, 30,000 injuries, and left 70,000 homeless. It caused extensive damage to residential and commercial buildings and emergency response facilities. In contrast to the inflicted human loss and suffering and extended building damage, lifeline systems, although damaged, performed much better. Transportation systems, i.e., roads, bridges, railways, and the airport, although slightly to moderately damaged, were generally operational soon after the earthquake to support emergency response and recovery effort. There were several breaks in the water distribution systems and minor damage to deep wells. However, the traditional qanat systems, which bring water from foothills tens of kilometers away via underground tunnels, were mostly damaged. The Bam area is served via connection to countrywide electric grid system. There was little damage to high voltage transmission lines and towers and minor damage to electric equipment in the main substation. Numerous concrete poles were damaged in the distribution system. There was nonstructural damage to telecom central offices. The main reason for the good performance of the lifeline facilities was that most of them are located outside the zone that was heavily damaged. Another reason is that they are newer facilities and in general more engineering has been used in lifeline facilities design and construction when compared with that for residential buildings.