A case study on the fire damage of the underground box structures and its repair works

Abstract

This study was performed to find out the damage of the underground box structures in Daegu Municipal Subway, South Korea, damaged by the fire broken out in February 18, 2003 through site inspection, material experiment and thermal stress analysis. As regards site inspection, net shape cracks, the stripping of concrete surface, the spalling of concrete, reinforcement exposure, were inspected. Likewise as regards material experiments, core specimens were collected in case of the region damaged seriously in order to evaluate uniaxial compressive strength. Thermal stress analysis was conducted centering around the two regions damaged seriously on the basis of the results of the site inspection, on purpose to understand the variations in the stress of concrete slab according to the process of time. In addition, repair and reinforcement works were practiced to the region damaged, with intent to sustain long-term safety and such works were also dealt with. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. Reprinted with permission from Elsevier.