Journal of Korean Tunnelling and Underground Space Association ISSN:2233-8292(Print) 2287-4747(Online) 한국터널지하공간학회 논문집

In this study, fire resistance of a fireproof material sprayed upon an immersed tunnel was experimentally evaluated under HCinc and ISO834(duration of 4 hours) fire scenarios. Under HCinc fire scenario, the maximum inner temperatures of a concrete specimen at the depth of 0, 25 and 50 mm from the interface between the structure and the fire-proofing layer were 311°C, 194°C and 142°C respectively. Similarly, the corresponding maximum temperatures under ISO834 fire scenario were 332°C, 222°C and 179°C respectively. From the results, it was revealed that the two different fire scenarios assumed in this study have almost the same fire capacity as each other in the maximum temperature concept. In addition, a structural analysis of the immersed tunnel under HCinc fire scenario was carried out to verify the effects of the fireproof material on its structural stability. Material loss and deterioration of a concrete specimen without any fire-proofing measure was also experimentally evaluated to obtain input parameters for the structural analysis under such a severe fire scenario. From the results, it was confirmed that the application of fireproof measures to the immersed tunnel is essential for its structural stability even under a severe fire scenario.