Flood Influence Characteristics of Rail Transit Engineering of Tunnel, Viaduct, and Roadbed through Urban Flood Detention Areas

Many subways, light rails, and trains travel through urban flood retention regions via tunnels, viaducts, and roadbeds; however, less is known about the flood influence laws of rail transportation by the crossing ways. Rail transit projects were chosen as research objects for the ordinary subway, light rail, and railway passing through urban flood detention areas in Wuhan, and the flood influence characteristics were systematically compared for the three crossing ways. The study revealed that crossing ways primarily affected the flood storage volume occupied per unit length of lines and that the flood influence of rail projects on flood detention areas was proportionate to the flood storage volume occupied per unit length of lines. Specifically, the flood storage volume occupied per unit length of tunnels was about 1/8.9 that of viaducts and 1/19.7 that of roadbeds. Moreover, the tunnel way had the least influence on the main aspects, such as flood control, floods on engineering, and engineering-related aspects; the roadbed-based way had the largest; and the viaduct way was in the middle. These findings may provide technical support for the decision-making, engineering planning, construction, and management of rail transit and other projects in urban flood detention areas.