Abstract:

A Shenzhen Jihe highspeed doubledeck shield tunnel case study is being conducted to realize smoke extraction, evacuation, and rescue in a superlarge crosssection highway tunnel. Then, under varied fire conditions, the smoke extraction characteristics, temperature field, and visibility distribution at the conventional and bifurcated crosssection of the tunnel are investigated with FDS numerical simulation method. It is recommended that the longitudinal wind speed of the tunnel should be kept within 3 m/s. A comprehensive study on the emergency rescue of highway tunnel fire accidents is conducted based on the causes and characteristics of a highway tunnel fire. Furthermore, a simulation method is used to calculate six evacuation conditions in the case of multiple groups of stair parameters, and it is established that the safety evacuation requirements can be met when the crosspassage spacing is 250 m and the stair spacing is 80 m. Finally, the fire emergency rescue strategy system of the superlarge crosssection doubledeck highway tunnel is proposed, and the rescue evacuation route and smoke extraction strategy for the Jihe highspeed doubledeck shield tunnel are put forward.

Key words: highway tunnel, superlarge crosssection tunnel, fire characteristics, evacuation and rescue system, smoke extraction strategy