鐵路地下隧道及車站之防火性能設計研究

Abstract

因地下場站防火設計無法以一般規格性法規來進行設計，因此本研究 利用性能式設計法（performance-based design method）之驗證程序和步驟，以及數值火災模擬軟體FDS（Fire Dynamics Simulator）和SIMULEX 人員逃生避難軟體分別針對地下車站公共區以及軌道區進行案例分析，來確保其消防設備的性能能夠確實的達到保障人員安全的目標。另外，針對地下隧道進行案例分析，探討隧道通風設備對煙流的影響。 本研究共模擬兩個案例，案例一主要分為軌道區火災及車站火災模擬 兩個部份。案例二為隧道火災模擬。在分析的過程中，首先以火災模擬軟體FDS 模擬火災的煙層流動情形、CO 濃度分佈、溫度分佈及能見度分佈來計算出所能提供人員疏散的時間。接著再利用動態避難模擬SIMULEX模擬計算人員避難逃生情形和避難所需時間，以評估人員避難安全。由案例一模擬結果可得，由於車站內採用分區排煙設計，此設計可以集中排煙風機的抽風能力，對特定區劃進行排煙，增強排煙效果，因此可減緩煙塵影響逃生避難空間的速度，增加旅客逃生避難的時間。另外，經由軌道區火災案例之模擬結果發現，利用UPE(Under Platform Exhaust)切換OTE(Over Track Exhaust)並隨後開啟TVF(Tunnel Ventilation Fan)的控制模式，有助於延後月台層逃生環境受到火災影響的時間。而在案例二模擬結果可得，增設隧道通風設備能有效控制煙流的方向，增加人員逃生的時間。最後經由數值模擬結果比對逃生時間後可得知，所有案例均能滿足人員生命安全的 標準，並可讓地下車站建築設計者作為逃生避難及煙控設計之參考。

The fire safety design of underground station generally cannot meet the requirements by building and fire codes, therefore, this research carried out the case studies for track and public areas of underground station by utilizing the design procedures of performance-based design method and the numerical simulation softwares, FDS（Fire Dynamics Simulator）and Simulex. It needs to ensure that the performance of fireproof equipments can retain the goal of occupant safety. In another case, it is to analyze the smoke movement in the underground railroad tunnel for investigating how the smoke management system affect its movement in tunnel. In this research, two case studies were chosen. Case 1 was further divided into three fire scenarios; fire sources were located at track (scenario 1), platform (scenario 2) and concourse (scenario 3) areas, respectively. Case 2 concerned on the fires occurred in tunnel. In the process of simulation, FDS was firstly used to simulate the fire growth and smoke movement, CO concentration and temperature distributions, and visibility. After that, a dynamic egress model, SIMULEX, was applied to calculate the situations of evacuating occupants and the corresponding available evacuation time to justify the safety level of egress. From the simulation results in Case 1, they showed that the station area, including the platform and concourse, facilitates the sub-compartmental desmoke system so that can utilize the full capacity of smoke exhaust fan for the particular region, such as fire origin area, to enhance the smoke effect and to mitigate the smoke influence on occupant traveling speed. Therefore, the evacuation time can be prolonged. As to the train fires at underground station trackway, it was found to turn off the under platform exhaust (UPE) and turn on the over track exhaust (OTE) simultaneously, and start tunnel ventilation fan (TVF) later can effectively exhaust smoke to keep the whole station attainable. Such installations and desmoke procedure are very helpful for mitigating the fire/smoke influence on the evacuation route that increase the escaping time from the platform to the safe area. From the simulation results of tunnel fire, they showed that the existing tunnel ventilation facilities are capable of controlling the direction of smoke effectively so that the available evacuation time in tunnel can be increased. To summarize, all of the fire protection designs in the station are found to be able to comply with the life safety requirements for occupant evacuation. And the results of this research can serve as a proper reference for smoke control system design and evacuation plan for underground station.