长大公路隧道火灾安全疏散性能化设计与分析

基于性能化防火设计方法, 分析火灾条件下长大公路隧道内人 员疏散行为的特点,给出隧道内人 员疏散的安全判据,并结合某隧道 的结构及车流特征对人员疏散过程 进行了数值模拟研究,分析隧道在 正常通车和局部行车堵塞时,不同 火源位置、横通道间距与横通道宽 度对人员疏散时间及安全状态的影 响。结果表明,与建筑内人员疏散不 同,长大公路隧道内火灾的可用安 全疏散时间(ASET)与需要的安全疏 散时间(RSET)均为沿隧道长度方向 位置的函数。隧道内人员安全疏散 的时间曲线在各横通道疏散口出现 峰值,这主要是受到横通道通行能 力的限制,各疏散口人员集聚等待 所致。当隧道发生局部堵塞时,横 通道口需要的安全疏散时间显著增 加,危险性也急剧增大。隧道内人 员疏散的性能化防火设计应综合考 虑火源位置对人员载荷及疏散口位 置可用安全疏散时间的影响。该研 究为公路隧道火灾安全疏散设施的 优化设计提供依据。     

Modeling emergency evacuation for major hazard industrial sites

A model providing the temporal and spatial distribution of the population under evacuation around a major hazard facility is developed. A discrete state stochastic Markov process simulates the movement of the evacuees. The area around the hazardous facility is divided into nodes connected among themselves with links representing the road system of the area. Transition from node-to-node is simulated as a random process where the probability of transition depends on the dynamically changed states of the destination and origin nodes and on the link between them. Solution of the Markov process provides the expected distribution of the evacuees in the nodes of the area as a function of time. A Monte Carlo solution of the model provides in addition a sample of actual trajectories of the evacuees. This information coupled with an accident analysis which provides the spatial and temporal distribution of the extreme phenomenon following an accident, determines a sample of the actual doses received by the evacuees. Both the average dose and the actual distribution of doses are then used as measures in evaluating alternative emergency response strategies. It is shown that in some cases the estimation of the health consequences by the average dose might be either too conservative or too non-conservative relative to the one corresponding to the distribution of the received dose and hence not a suitable measure to evaluate alternative evacuation strategies.     

基于行为认知分析的消防疏散图设计研究

目的 通过分析用户疏散过程与使用消防疏散图过程的行为与认知,探讨消防疏散图产品定位和视觉设计策略。方法 通过行为观察、访谈、实验方法分析用户疏散行为与认知过程,梳理用户认知要点和需求;通过行为观察、访谈方法,结合认知理论,分析用户使用消防疏散图行为与认知过程;采用眼动仪实验和主观评价获取数据,并进行相关性分析,分析用户使用消防疏散图认知过程的关键视觉影响因子。结论 梳理了用户消防疏散的行为过程、所需信息和信息区域;梳理了消防疏散图中影响用户认知的视觉影响因子;通过眼动仪实验获取了用户使用疏散图的认知效率数据,并分析了视觉影响因子与认知效率的相关性。在以上研究基础上提出消防疏散图的原则与策略。     

Diesel oil pool fire characteristic under natural ventilation conditions in tunnels with roof openings

In order to research the fire characteristic under natural ventilation conditions in tunnels with roof openings, full-scale experiment of tunnel fire is designed and conducted. All the experimental data presented in this paper can be further applied for validation of numerical simulation models and reduced-scale experimental results. The physical model of tunnel with roof openings and the mathematical model of tunnel fire are presented in this paper. The tunnel fire under the same conditions as experiment is simulated using CFD software. From the results, it can be seen that most smoke is discharged directly off the tunnel through roof openings, so roof openings are favorable for exhausting smoke. But along with the decrease of smoke temperatures, some smoke may backflow and mix with the smoke-free layer below, which leads to fall in visibility and is unfavorable for personnel evacuation. So it is necessary to research more efficient ways for improving the smoke removal efficiency, such as early fire detection systems, adequate warning signs and setting tunnel cap.     

A modified entropy-based dynamic gravity model for the evacuation trip distribution problem during typhoons

Typhoon Morakot, which formed on 2 August 2009, was the deadliest typhoon in Taiwan’s history, responsible for over 700 deaths on the island. During the typhoon evacuation process, one critical issue is how to efficiently distribute the evacuation trips to a limited number of shelters based on both spatial and temporal considerations. This paper proposes a modified entropy-based dynamic gravity model to reflect the spatial and temporal distribution of the evacuees and the shelters. A unique feature of the proposed model is that the entropy is explicitly incorporated within the travel cost constraints. The spatial and temporal relationships between evacuees and shelters can be reflected through the impedance functions and the discretized time intervals with better performance than the traditional model. A simulation-assignment model is applied to generate the zone-to-zone travel time. A calibration analysis based on the solution procedure is conducted for the Jiasian network, in Kaohsiung city, which was heavily affected by the Typhoon Morakot. The calibration results show that the modified entropy-based dynamic gravity model leads to better convergence patterns in the entropy values, higher travel cost coefficients, and lower average generalized trip costs than the traditional model, and is suitable for use with the evacuation plan during typhoons.     

布达拉宫古建筑的火灾风险分析

利用火灾风险分析的方法对具有重要历史和文物价值的布达拉宫古建筑进行安全评估。以建筑自身状 况、着火源控制、消防设施配备、人员疏散设施以及消防安全管理等方面的现状为切入点,对布达拉宫重点区域 作了火灾危险性调查。在此基础上,引入半定量的火灾风险分析方法,分析影响布达拉宫古建筑火灾风险水平的 各因素。对体现火灾风险重要性的各参数划分等级并对其进行赋值。通过计算布达拉宫古建筑部分重点区域的火 灾风险值,分析不同区域的相对火灾风险水平。最后提出一些火灾防治的对策。     

A method to optimize evacuation instructions

In this paper, an optimization method is presented for instructions to evacuate by car the population of a region threatened by a hazard. By giving the optimized instructions to the evacuees, traffic conditions and, therefore, the evacuation efficiency are optimized. The instructions, containing a departure time, a safe destination, and a route, are created using an optimization method consisting of two phases: the generation of the search space and the algorithm AES⁺ evacuation, a version of ant colony optimization. The main contributions of the proposed optimization method are the unique approach to generate the search space in which network degeneration is taken into consideration, the possibility to optimize instructions under the assumption of both full and partial compliance of the evacuees with the instructions, and the flexibility in the sense that the user of the method can define his or her own objective function and choose a suitable traffic simulation model. The paper contains a comprehensive case study. The case study shows that the effectiveness of the optimized instructions is more than doubled when compared with the effectiveness of instructions set up by straightforward rules (like evacuating to the nearest destination using the shortest route). Further, the case study shows that the number of arrivals under optimized, but possibly sub-optimal instructions is equal to at least 90% of the theoretical upper bound on this number of arrivals.     

基于几何方法的人员疏散最佳路径

防火防灾中的人员疏散研究具有十分重要的意义。传统的方法多采用网格法来确定最佳路径,由于人员个体只能在网格中运动,模拟很难准确。本文首次提出基于几何的人员疏散模型,人可以沿任意方向运动,考虑了人员个体与障碍物、人员个体之间的碰撞检测,按照路径最短的原则确定出了人员疏散的方向和路径,在此基础上,对单个房间内的人员疏散过程进行了模拟。算例结果表明,本文的方法对疏散过程模拟得更真实、更精确,是一种有效的模拟人员疏散过程的手段。     

A robust bus evacuation model with delayed scenario information

Due to natural or man-made disasters, the evacuation of a whole region or city may become necessary. Apart from private traffic, the emergency services also need to consider transit-dependent evacuees which have to be transported from collection points to secure shelters outside the endangered region with the help of a bus fleet. We consider a simplified version of the arising bus evacuation problem (BEP), which is a vehicle scheduling problem that aims at minimizing the network clearance time, i.e., the time needed until the last person is brought to safety. In this paper, we consider an adjustable robust formulation without recourse for the BEP, the robust bus evacuation problem (RBEP), in which the exact numbers of evacuees are not known in advance. Instead, a set of likely scenarios is known. After some reckoning time, this uncertainty is eliminated and planners are given exact figures. The problem is to decide for each bus, if it is better to send it right away—using uncertain information on the evacuees—or to wait until the the scenario becomes known. We present a mixed-integer linear programming formulation for the RBEP and discuss solution approaches; in particular, we present a tabu search framework for finding heuristic solutions of acceptable quality within short computation time. In computational experiments using both randomly generated instances and the real-world scenario of evacuating the city of Kaiserslautern, Germany, we compare our solution approaches.     

某大型商贸中心的人员疏散性能化分析

新型建筑不断涌现使得火灾安全性能化设计被广泛应用，人员疏散是其中的关键环节。结合某大型商贸中心的火灾安全性能化设计方案，利用CAFE模型分析了人员疏散性能。结果表明，由于该模型量化了人员疏散过程中人与人、人与环境之间的作用力，因此计算得到的人员疏散时间比同类软件更加保守，分析结果具有更高的可靠性。     

自然通风城市隧道火灾温度分布试验研究

设定了两种火灾规模,以1：10模型比例对南京市某自然通风城市隧道进行了火灾时隧道内温度场的分布规律的模拟试验。试验结果表明,在大火灾强度下,温度场纵向影响范围相应增加;在隧道两口部存在温差的情况下,隧道内烟气主要向口部温度较高一侧的通风口扩散;在烟气经过通风竖井之后,烟气的温度有显著降低,证明自然通风竖井能够排出大量的烟气,并带走大部分热量,烟气会因热动力不足而发生沉降现象。     

Designing polymer matrix composite panels for structural integrity in fire

This paper discusses the compressive load bearing capability of polymer matrix composite panels in fire, a combined thermal and mechanical loading condition. An example of such combined loading condition is that of panels in ship structures under transverse thermal gradients caused by fire. Investigation is focused on failure modes under transverse thermal gradients and compressive mechanical loads, i.e. buckling, deflection induced by the shift of the neutral axis, thermal distortion without mechanical loads. Thermal field and mechanical fields for these failure modes are presented and discussed in details for the purposes of design considerations. Design diagrams are constructed to design mechanical loads for given fire protection time, and on the opposite, to design fire protection time for given mechanical loads. Unlike panels made by the conventional ship building material steel, the design diagrams for the temperature dependent materials with transverse thermal gradients consist of multiple failure mechanisms.     

水喷淋保护下单片防火玻璃耐热性能实验研究

针对单片防火玻璃在实际使用中背火面温度高而影响人员疏散的缺点，提出水喷淋保护方案。研究结果表明：在水喷淋保护下单片防火玻璃背火面温度和热辐射通量大大低于无水喷淋保护下的相应数值；快速响应水喷头在高温烟气作用下能够自动启动，可以长时间地保护防火玻璃，而且不会影响到防火玻璃背火面的人员安全疏散。     

Development of a variable speed limit strategy to reduce secondary collision risks during inclement weathers

Inclement weather reduces traveler's sight distance and increases vehicle's stopping distance. Once a collision occurred during inclement weather and resulted in a slow traffic, approaching vehicles may not have adequate time to make emergency responses to the hazardous traffic, resulting in increased potentials of secondary collisions. The primary objective of this study is to develop a control strategy of variable speed limits (VSL) to reduce the risks of secondary collisions during inclement weathers. By analyzing the occurrence condition of secondary collision, the VSL strategy is proposed to dynamically adjust the speed limits according to the current traffic and weather conditions. A car-following model is modified to simulate the vehicle maneuvers with the VSL control. Two surrogate safety measures, based on the time-to-collision notion, are used to evaluate the control effects of VSL. Five weather scenarios are evaluated in simulation. The results show that the VSL strategy effectively reduces the risks of secondary collisions in various weather types. The time exposed time-to-collision (TET) is reduced by 41.45%–50.74%, and the time integrated time-to-collision (TIT) is reduced by 38.19%–41.19%. The safety effects are compared to those with a previous VSL strategy. The results show that in most cases our strategy outperforms the previous one. We also evaluate how driver's compliance to speed limit affects the effectiveness of VSL control.     

大型超市安全疏散设计的初步研究

根据某大型超市的建筑设计方案以及人员分布情况,针对该超市各防火分区之间疏散楼梯分布不均 匀的问题,提出２种改进设计方案。一种是改进防火分区设置,在相邻防火分区之间设置共用楼梯,使得防火 分区的疏散宽度分布更均匀,另一种是缩小相关防火分区的面积从而增加一个防火分区。采用EVACNET４进行 计算机模拟,得到了３种疏散场景下人员疏散的时间。计算结果表明,当防火分区面积比较大时,疏散楼梯在 防火分区四周均匀分布有利于人员疏散;共用楼梯的设置,既有利于人员疏散,又可以提高楼梯的利用率;适 当减小防火分区的面积可以     

公路隧道垂直疏散通道设计参数研究

隧道疏散救援研究是当今地下工程领域一个重要的研究方向。为给公路隧道垂直疏散通道的参数设计提供依据,针对公路隧道中的滑梯、楼梯这两种常见垂直疏散通道的宽度、间距等参数进行了研究。基于人员在隧道中的实际疏散行为、运动速度等因素,考虑人员疏散行动中的反应,运用Pathfinder软件建立了隧道疏散模型。其中引入了“多米诺骨牌”阶段性效应将隧道按照与火灾点位置的不同划分为不同的响应时间区域。并利用前人的现场疏散实验数据验证了模型的准确性。考虑隧道全线堵塞、车辆满载的极端交通条件及火灾发生在隧道中间一处疏散通道位置的不利情况,研究了滑梯、楼梯不同间距及楼梯不同宽度对人员疏散时间及通过能力的影响。结果表明,楼梯宽度在0.8~1.1m之间每增加0.1m,通过能力增加约0.04人/s;宽度达到1.1m及以上时,每增加0.1m,通过能力增加约0.1人/s。在人员可用安全疏散时间(ASET)设定为8min的条件下,基于最长疏散时间及短暂聚集原则,通过对比分析得到了滑梯的最佳间距,拟合得到了楼梯最佳间距与宽度之间的关系式。此外,从降低建设成本及减小疏散口践踏等次发事故发生概率的角度考虑,相比于减小间距,增大楼梯的宽度更有利于人员的安全疏散。     

舰船细水雾灭火系统研究回顾

近十多年来，国际安全领域对细水雾灭火技术的研究方兴未艾，以美英等国海军为代表的西方各国海军对细水雾在舰船尤其是舰船动力机舱的应用进行了大量研究，结果令人振奋。对该领域的研究作了简单的回顾，旨在使国内安全领域的工作者对此有所了解，为我国海军在这方面的研究提供些许借鉴。     

建筑火灾人员疏散行动预测及仿真

人员疏散行动预测是用于疏散设计性能评价的工具。文章将建筑物划分为８种空间因素，用数学解析方法计算人员在各种空间因素内的疏散参数，从而实现对人员疏散行动的预测。在此预测方法的基础上，开发的人员疏散行动计算机仿真软件，使得预测方法具有实用性、可靠性及直观性。     

大空间内着火位置对火灾增长的影响

以大空间展厅为例,利用火源辐射模型和烟气辐射模型并结合CFAST6．0区域模拟软件的计算结果,对比分析了大空间内不同着火位置下火灾增长的情况。研究结果表明仅考虑火源热辐射的情况下,展厅内着火位置越处于左右中间对称处,其火灾增长越快,热释放速率峰值也越大,达到热释放速率峰值的时间和火灾的持续时间越短,处于展厅中心位置时所有值达峰值。对火源热辐射和烟气辐射综合考虑时,到达热释放速率峰值时间与火灾持续时间的规律同仅考虑火源辐射模型时一致,但热释放速率峰值均有不同程度的提高。     

常用室内装饰材料燃烧的FDS模拟分析

为了获取室内装饰材料的火灾安全性,应用FDS火灾动力学仿真软件分别模拟了PVC(聚氯乙烯)、PMMA(聚甲基丙烯酸甲酯)、PS(聚苯乙烯)三种常用装饰材料的燃烧特性.模拟结果显示,PMMA材料初始燃烧速率最快,50s内近火源温度接近500℃,PS次之,PVC较为缓慢,但在500s内温度可达500℃以上;450s时PVC燃烧的过门热流量达到130kW,为三者最高;PVC材料初始产烟效果要弱于PMMA、PS两种材料,但70s后烟层高度下压趋势更为明显.模拟结果可以为室内消防设计及火灾现场人员的安全疏散提供参考依据.