Influence of Staircase Design on Flood Characteristics in Underground Spaces

Abstract

<p>Underground flooding events are intensifying due to the rapid expansion of urban underground spaces and frequent extreme precipitation events caused by climate change. Due to the vulnerability of urban underground spaces to such flooding events and the fact that access to underground spaces is generally in the form of staircases, it is of both academic and practical value to explore the evolution of flooding on underground staircases. This work investigates the flood dynamics characterized by water depth and flow velocity on different types of staircases in underground spaces. A numerical model based on the twodimensional (2D) shallow water equations (SWEs) is established to simulate flooding on staircases of different designs. Results show that shorter or higher steps lead to shallower water depths and higher flow velocities, with step length exerting a greater impact on flood dynamics than step height. For the staircase with junction, the branch line experiences significantly lower water depths and flow velocities compared to the main line.</p>