Innovative Construction Pathways and Optimization Strategies for Underground University Sports Complexes from a Fire Evacuation Wayfinding Perspective

The increasing scarcity of land on university campuses, together with the growing demand for multifunctional sports facilities, has made stacked sunken sports buildings an important spatial model for improving land-use efficiency in high-density campuses. By vertically stacking above-ground sports fields with underground or semi-underground sports spaces, this model reduces horizontal land occupation while introducing complex design issues related to long-span structures, vertical circulation, daylighting, and multilevel emergency evacuation. Based on a survey of representative cases, project design data, and fire evacuation wayfinding simulations, this study takes the Sports Center of North China Electric Power University as the base model to examine the effects of emergency exit dimensions and locations, evacuation route length, and sunken plaza connectivity on evacuation wayfinding efficiency. The multifunctional role of sunken plazas in circulation organization, emergency evacuation, and campus public space integration is also examined. Under the specified case geometry and parameter settings, evacuation time tends to stabilize when the emergency exit width reaches 1.5–2.0 m. Among the three tested evacuation route lengths of 20, 23, and 26 m, the 23 m configuration yields the shortest overall evacuation time. A fully connected sunken plaza configuration with multiple exits achieves relatively shorter evacuation times under both fire scenarios. The study therefore identifies three simulation-supported implications—distributed exit organization, route–node coordination, and multi-exit sunken plaza connectivity—while structural and landscape recommendations are presented as case-informed architectural implications; the findings provide a performance-oriented reference for comparable stacked sunken sports buildings.