Study on fire resistance range and fire protection of tunnels with side concentrated smoke exhaust
Zhu Hangkai1,2
(1. China Railway Siyuan Survey and Design Group Co.，Ltd.，Wuhan 430063, Hubei, China；
2. National & Local Joint Engineering Research Center of Underwater Tunnel Technology, Wuhan 430063, Hubei, China）
摘要 为确定双层侧部重点排烟盾构隧道的结构防火保护范围，基于德国道路隧道升温曲线（Richtlinien für die Ausstattung und den Betrieb von Stra?entunneln，RABT）反演确定上层35 MW、下层30 MW的火灾热释放速率，并采用FDS建立隧道数值模型，设置15 MW常规火灾与标准火灾、排烟有效与失效等多工况，开展火灾温度场与耐火极限区域模拟。结果显示，上层隧道拱顶耐火极限最大面积为512 m2，需对拱顶横向10 m、竖向自顶部向下2 m范围实施防火保护，侧墙无超温区域；下层隧道顶板最大面积为498 m2，侧墙在最不利工况下超温范围自顶板向下延伸2.5 m，需对顶板横向10 m及侧墙竖向2.5 m范围实施防火保护。上述结论可为同类双层盾构隧道侧部重点排烟模式下的结构抗火设计提供量化依据。
Abstract: The structural fire protection scope for a double-deck shield tunnel with side-focused smoke exhaust was determined.The fire heat release rates corresponding to the temperature-time curve specified in the German Guidelines for the Equipment and Operation of Road Tunnels (Richtlinien für die Ausstattung und den Betrieb von Stra?entunneln, RABT) were inversely determined as 35 MW for the upper tunnel and 30 MW for the lower tunnel. A numerical tunnel model was established using fire dynamics simulation software (fire dynamics simulator, FDS), and multiple scenarios were simulated, including a 15 MW conventional fire, standard fires, and effective and failed smoke exhaust conditions. The fire-induced temperature fields and zones reaching the fire-resistance limit were investigated.The results showed that the maximum area of the fire-resistance-limit zone at the vault of the upper tunnel was 512 m2. Fire protection was therefore required over a transverse width of 10 m and a vertical extent of 2 m downward from the vault, whereas no overtemperature zone was observed on the sidewalls. For the lower tunnel, the maximum area of the fire-resistance-limit zone on the roof slab was 498 m2. Under the most unfavorable condition, the overtemperature zone on the sidewalls extended 2.5 m downward from the roof slab. Accordingly, fire protection was required over a transverse width of 10 m on the roof slab and a vertical extent of 2.5 m on the sidewalls. These findings provided a quantitative basis for the fire-resistant design of similar double-deck shield tunnels employing a side-focused smoke exhaust mode.
朱航凯. 侧部重点排烟隧道耐火极限范围及防火保护研究[J]. 隧道与地下工程灾害防治, .
Zhu Hangkai. Study on fire resistance range and fire protection of tunnels with side concentrated smoke exhaust. Hazard Control in Tunnelling and Underground Engineering, 0, (): 1-12.
