Evaluating the impact of tunnel slope on critical velocity and confinement velocity in metro tunnel carriage fires

IF 6.7 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology Pub Date : 2024-10-14 DOI:10.1016/j.tust.2024.106141

Zhihe Su , Yanfeng Li , Hua Zhong , Junmei Li , Boyu Li , Siyan Kang , Youbo Huang

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引用次数: 0

Abstract

Smoke control within metro tunnels stands as a pivotal measure in ensuring both the orderly evacuation and safety of passengers. This study investigated the critical velocity and confinement velocity in inclined metro tunnel fires via model-scale experiments. The tunnel slope varied from 2 % ∼ 8 % and four fire heat release rates of 2.29 kW, 3.44 kW, 4.59 kW and 5.74 kW. Results show that the confinement velocity and critical velocity monotonically increase with the heat release rate and tunnel slope. The confinement velocity V_conf was notably affected by the equivalent fire source Q_u. The natural exponential function could effectively express the relationship between Q* and Q_u*, with the correction factor of tunnel slope utilized to adjust the expression. A new model for critical velocity and confinement velocity was characterized by considering the tunnel slope and heat release rate. Comparative results indicated that the optimizing confinement velocity was significantly lower than that defined in previous studies, while the proposed critical velocity ratio aligns well with findings from prior research. This study provides valuable insights into the design of smoke control systems customized for fires occurring in trains immobilized within inclined underground tunnels.

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评估隧道坡度对地铁隧道车厢火灾临界速度和限制速度的影响

地铁隧道内的烟雾控制是确保乘客有序疏散和安全的关键措施。本研究通过模型实验研究了倾斜地铁隧道火灾的临界速度和封闭速度。隧道坡度为 2 % ～ 8 %，火灾热释放率分别为 2.29 kW、3.44 kW、4.59 kW 和 5.74 kW。结果表明，封闭速度和临界速度随着热释放率和隧道坡度的增加而单调增加。封闭速度 Vconf 受到等效火源 Qu 的显著影响。自然指数函数可以有效地表达 Q* 和 Qu* 之间的关系，并利用隧道坡度的修正系数来调整表达式。通过考虑隧道坡度和热释放率，建立了一个新的临界速度和限制速度模型。比较结果表明，优化的封闭速度明显低于之前研究中定义的速度，而提出的临界速度比与之前的研究结果非常吻合。这项研究为设计专门针对固定在倾斜地下隧道内的列车火灾的烟雾控制系统提供了宝贵的见解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Tunnelling and Underground Space Technology 工程技术-工程：土木

CiteScore

11.90

自引率

18.80%

发文量

454

审稿时长

10.8 months

期刊介绍： Tunnelling and Underground Space Technology is an international journal which publishes authoritative articles encompassing the development of innovative uses of underground space and the results of high quality research into improved, more cost-effective techniques for the planning, geo-investigation, design, construction, operation and maintenance of underground and earth-sheltered structures. The journal provides an effective vehicle for the improved worldwide exchange of information on developments in underground technology - and the experience gained from its use - and is strongly committed to publishing papers on the interdisciplinary aspects of creating, planning, and regulating underground space.