Abstract: To realize smoke control for an underground space loop with multiple ramps, blocks, and complex internal spaces, a segmented smoke exhaust method is proposed. This involves separating the underground space loop from the land using fire doors, thereby creating an independent structure. The location of the air room is determined according to the tunnel structure, facilitating the division of smoke into sections for discharge within certain areas. This methodology is applied in a case study on the Bingjiang underground loop. Here, the tunnel is divided into eight sections by evenly arranging six smoke exhaust rooms on the main line and using them as nodes. In the event of a fire, the fans at both ends of each section initiate smoke exhaust. Given that there are no fixed separations between each section, the entire air duct remains interconnected. As such, the fans in each fan room can serve as backup smoke exhaust fans to reduce costs. The numerical simulation software is used to establish a model to simulate the number and spacing of smoke exhaust ports. From this, it is determined that the optimal smoke exhaust scheme involves a smoke exhaust volume of 90 m3/s, a distance of 30 m between smoke exhaust ports, and eight smoke exhaust ports. Then typical sections are evaluated in terms of their evacuation environment and smoke exhaust efficiency. The results show that smoke is effectively controlled within a certain range, ensuring a safe evacuation environment. Moreover, the smoke extraction efficiency reaches 90%, proving the rationality and the feasibility of the proposed method.

Key words: fire smoke control, underground space loop, ventilation and smoke exhaust design method, section division