Evaluation of Casualty Risk Index for Evacuating When Inundation Occurs on Excavation Construction Sites

Abstract

Recently, inundation accidents occur repeatedly on underground excavation construction sites owing to frequent intensive rainfall events. In the case of the inundation of underground construction sites, injury and drowning accidents may occur on the evacuation route. However, no method or standard for calculating the risk of casualty while evacuating workers has been proposed. In this study, we defined the casualty risk index (CRI) and developed a method for estimating CRI. We adopted the “HV,” which is the product of height (water depth) and velocity (water velocity) recommended by previous researches. The “HV” indicates that humans can walk safely in water flow without stumbling. The proposed method was applied to a hypothetical underground construction site in the city of Yeosoo. ArcGIS Pro was used to model the hypothetical excavation site, and XPSWMM was used to simulate rainfall runoff and two-dimensional hydraulic simulation. While the runoff was flowing into an underground construction site, we simulated the water height and water velocity on the evacuation route to estimate the CRI. The results showed that CRIs from various rainfall scenarios remained in the safe criteria, indicating that workers could safely evacuate from the site in the rainfall scenarios. However, the CRI is influenced by site-based factors, and these factors are discussed.