Structural Performance Assessment of Sliding-Type Evacuation Ladders Under Realistic Fire Evacuation Loading Conditions

This study evaluates the structural performance of sliding-type evacuation ladders under realistic fire evacuation loading conditions using parametric numerical analysis. A series of finite element models was developed based on the original ladder design, and key parameters—including member thickness (1–4 mm), overlap length between modular units (40–70 mm), loading configurations, and boundary conditions at the ladder base—were systematically varied. A total of 288 numerical cases were analyzed to investigate their influence on global displacement behavior. The results indicate that a minimum member thickness of 2 mm is required to satisfy displacement-based serviceability criteria; however, this threshold may be insufficient when connection flexibility is considered. The overlap length has a more pronounced effect on structural performance for thinner members, while the loading height has a significant effect on the displacement response. In addition, the boundary condition at the ladder base plays a critical role, with vertical support conditions substantially reducing overall displacement. These findings highlight the importance of system-level structural evaluation beyond component-based testing. They also provide practical insights for improving the design criteria and installation conditions of evacuation ladders in high-rise residential buildings during fire emergencies.