Numerical Simulation of Flood Intrusion Process under Malfunction of Flood Retaining Facilities in Complex Subway Stations

Abstract

In recent years, heavy rain and waterlogging accidents in subway stations have occurred many times around the world. With the comprehensive development trend of underground space, the accidents caused by flood flow intruding complex subway stations and other underground complexes in extreme precipitation disasters will be lead to more serious casualties and property damage. Therefore, it is necessary to conduct numerical simulation of flood intrusion process under malfunction of flood retaining facilities in complex subway stations. In order to prevent floods from intruding subway stations and explore coping strategies, in this study, the simulation method was used to study the entire process of flood intrusion into complex subway stations when the flood retaining facilities fail in extreme rain and flood disasters that occur once-in-a-century. The three-dimensional numerical simulation model was constructed by taking a subway interchange station with a property development floor in Nanning as a prototype. Based on the Volume of Fluid (VOF) model method, the inundated area in the subway station during the process of flood intrusion from the beginning to the basic stability was simulated, and it was found that the property development floor has serious large-scale water accumulation under extreme rainfall conditions. Through the dynamic monitoring of the flood water level depth at important positions such as the entrances of the evacuation passages, and the analysis of the influence of the design structure and location distribution of different passages on the personnel evacuation plan, it was found that the deep water accumulation at the entrances of the narrow, long, and multi-run emergency safety passages are not conducive to the evacuation of personnel. Finally, the flow of flood water into the subway tunnel through the subway station was calculated. The research results provide certain reference and guidance for the safety design of subway stations under extreme rainfall climatic conditions.

Evaluation of Flooding Disaster Risks for Subway Stations Based on the PSR Cloud Model

“…In physical modeling, researchers utilize hydrodynamic models to simulate flooding scenarios. For example, Edwar Forero-Ortiz [6] employed a 1D/2D hydrodynamic model, Zhiyu Lin [10] developed a 3D numerical simulation model based on the VOF (Volume of Fluid) model, Colombo [11] used a stochastic model that transformed a 3D numerical model, and Lyu [12] combined the stormwater management model SWMM (Storm Water Management Model) with the GIS (Geographic Information System) to simulate flood hazards in metro systems. On the other hand, statistical modeling approaches involve analyzing data and performing simulations based on statistical analysis.…”

Flow Pattern and Escape Hazards of People from Flood Intrusion into the Staircase of Underground Spaces with Multiple Rest Platforms

“…Tang, Zhou [21] simulated the evacuation process of people after the subway station flooded, analyzed the influencing factors of safe escape, and obtained the critical escape water depth for people at the station. Lin, Hu [22] built a computational fluid dynamics model of a subway station, simulated the whole process of flood intrusion, and proposed the dangerous areas and evacuation routes under different water depths and invasion passages. Inoue, Toda [23] focused on the danger zone created at the staircase when the flood intrudes into the underground space and found that the flow rate and water depth of the flood on the staircase are closely related to the escape of people; they also proposed an escape judgment function, as follows:…”

Are the epidemic prevention facilities effective? How cities should choose epidemic prevention facilities: Taking Wuhan as an example

“…In fact, epidemic prevention facilities are rarely mentioned in comprehensive disaster prevention and mitigation plans for cities around the world (20,21). Most of the studies about urban disaster facilities focus on assessing the ability of cities to cope with natural disasters from the perspectives of floods, fires, and earthquakes, combing with population data, urban infrastructure, social factors and so on (7,(22)(23)(24)(25). Existing studies indicate the characteristics and development trends of global urban disasters and major emergencies, comparing the advantages and disadvantages of urban disaster prevention facilities and conducting a macroscopic assessment of urban emergency measures to optimize the disaster prevention planning (26)(27)(28).…”