Abstract As for the Jintang Subsea Tunnel on Ningbo-Zhoushan Railway, the numerical simulation method is used to analyze the stress, deformation and deterioration of shield tunnel lining structure induced by fire under the RABT standard heating curve, and to investigate the fire resistance of segmental lining structure of large-diameter shield tunnel under high temperature of fire and the fire resistance measures. As the results suggest, after 120 min of exposure to fire under the RABT heating curve, the fire heated surface of concrete lining reaches 1,119 ℃, so the lining structure cannot meet the fireproofing design requirements; the concrete lining starts deterioration after 5.3 min of exposure to fire, the failure zone continues expanding as the duration of fire increases, and when the fire stops, the maximum deterioration depth is greater than 12 cm; in addition, when the fire stops, the clearance convergence of the tunnel in both vertical and horizontal directions decreases as compared with that before the fire, and the absolute value of the decrease is 11.5 mm and 0.12 mm respectively; the 3 techniques, i.e. installing concrete refractory layer on segments, installing fire board and applying fire-resistant coating, will effectively enhance the fire resistance of the lining structure, but with comprehensive consideration of the factors such as suitability in practical engineering,it is recommended to use the C40 concrete refractory layer with ≥8 cm thickness or the fire-resistant coating with thermal conductivity <0.15 W/(m·K).
Abstract：
As for the Jintang Subsea Tunnel on Ningbo-Zhoushan Railway, the numerical simulation method is used to analyze the stress, deformation and deterioration of shield tunnel lining structure induced by fire under the RABT standard heating curve, and to investigate the fire resistance of segmental lining structure of large-diameter shield tunnel under high temperature of fire and the fire resistance measures. As the results suggest, after 120 min of exposure to fire under the RABT heating curve, the fire heated surface of concrete lining reaches 1,119 ℃, so the lining structure cannot meet the fireproofing design requirements; the concrete lining starts deterioration after 5.3 min of exposure to fire, the failure zone continues expanding as the duration of fire increases, and when the fire stops, the maximum deterioration depth is greater than 12 cm; in addition, when the fire stops, the clearance convergence of the tunnel in both vertical and horizontal directions decreases as compared with that before the fire, and the absolute value of the decrease is 11.5 mm and 0.12 mm respectively; the 3 techniques, i.e. installing concrete refractory layer on segments, installing fire board and applying fire-resistant coating, will effectively enhance the fire resistance of the lining structure, but with comprehensive consideration of the factors such as suitability in practical engineering,it is recommended to use the C40 concrete refractory layer with ≥8 cm thickness or the fire-resistant coating with thermal conductivity <0.15 W/(m·K).
XIAO Mingqing1,
2 YANG Wenqian3 FENG Kun3 JIAO Qizhu1 MAO Sheng1 WANG Yunchao3
.Simulation Analysis of the Forces on Lining Structure of Shield Tunnels and Fire Resistance Measures during Fire[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(3): 199-207
2023, Vol. 60 