地铁车站人员疏散离散时间模型研究

疏散时间对于保证地铁车站这类复杂建筑结构内人群的安全至关重要,本文借鉴群集流动理论建立了用于计算地铁车站人群移动时间的疏散离散时间模型(EDTM),模型中的人群流动系数取值不同于传统计算公式中的常量,依据的是经典的车站人群密度与速度函数关系式。将此模型用于某地铁车站站台层,求解楼梯出口疏散人数与时间的关系,并与Building EXODUS疏散软件的模拟结果以及传统地铁车站疏散时间计算公式的计算结果进行了对比,分析表明,EDTM计算结果与EXODUS疏散模拟结果非常接近,且比传统公式计算更为精确和符合实际情况。该计算模型可以为地铁车站人群疏散时间计算、建筑出口性能化设计,以及地铁车站事故应急预案的制定提供更有效的工具。     

突发灾害事件情境下人群疏散研究进展

灾害发生时如何将居民在最短时间内疏散到安全区域,是城市规划和应急管理面临的重要问题。基于大量国内外文献,梳理了人群疏散的研究内容、理论、方法及数学模型,总结了人群疏散时间和效率的影响因素,比较了疏散研究领域各类方法、模型的优劣点以及应用场景。已有的人群疏散研究方法及实证研究成果较多,但在应用尺度上主要聚焦于建筑尺度,与当前城市防灾规划与应急管理存在一定脱节。此外,对于多灾种、次生灾害下的疏散研究未能涉及,在社区尺度疏散研究中未能考虑疏散人群的特异性和灾害的动态影响。未来需进一步探索次生灾害、多灾种下人群疏散研究方法,将人群疏散研究结果应用于防灾规划及规范制定,同时关注特殊人群的应急疏散研究。     

垂直升船机初期火灾疏散路径人群流量分配研究∗

为合理分配垂直各疏散路径的人群流量,通过分析垂直升船机的结构特征,确定升船机综合使用电梯与楼梯进行垂直疏散的可行路径,分别计算从电梯向最近出口疏散、经楼梯向上游平台疏散、经楼梯向下游平台疏散等三条路径上的疏散时间,取三者较大值作为升船机垂直疏散时间,并以此时间最小化为目标函数,运用粒子群算法,仿真求解使用楼梯比例及向上游平台疏散比例等流量分配系数。结果表明:停靠高程∈[62,128]m时,楼梯使用比例可适当增大,使用楼梯向上游疏散比例为0;停靠高程∈[128,147]m时,楼梯使用比例可进一步增大;停靠高程∈[147,175]m时,楼梯使用比例可适当减小,使用楼梯向上游疏散比例为1,经流量分配后疏散时间被有效缩短。     

海岸带综合防灾安全疏散系统风险评估及优化——以厦门市为例

海岸带处于海陆交界的特殊地带,受自然和人为因素的影响,极易发生各类灾害。如何做好防灾减灾尤其是安全疏散工作,是海岸带区域“陆海统筹”的一项重要工作内容。首先,通过分析海岸带区域的灾害特征提取出台风、洪涝、地震和火灾四类典型灾害;其次,以点(疏散人群)、线(疏散通道)、面(疏散场所)要素梳理安全疏散系统空间构成;随后,以四类典型灾害为例,基于自然灾害风险指数法构建综合防灾视角下的安全疏散系统风险评估模型,包含致灾因子危险性(H)、承灾体暴露性(E)、孕灾环境敏感性(V)和安全疏散能力(C),并进一步将其解构为包含1个目标层、4个准则层、14个方案层和35个指标层的四级评估指标体系;最后,对厦门市进行实证研究,分析风险评估结果并总结特征,在韧性城市理念的指导下提出构建安全疏散空间体系、建立灾害应急管理机制的安全疏散系统优化策略。     

多约束多目标的灾害避难所选址优化研究——以海南省文昌市为例

地震灾害避难所优化选址是灾害管理的一个重要内容,也是个难点。以最小化总疏散距离和最小化避难所总面积为目标,同时在满足距离约束和容量约束的条件下,建立地震灾害避难所选址多目标模型,采用改进的粒子群算法对模型进行解算,并以海南省文昌市为例进行实证分析。结果表明:距离约束在多目标模型的空间分配结果中起主导作用,容量约束则会显著影响多目标模型及其算法在高维复杂问题中的空间搜索能力和解的质量。优化结果可为灾害避难所区位的确定及疏散方案的制定提供科学依据,为震后应急疏散提供决策支持。     

灾害条件下多层次应急疏散模型的构建方法研究

人们每天都要面对各种造成严重财产和人身安全损失的重大灾害,如何建立灾害条件下中国人口高密度大范围的应急疏散模型,具有重大的意义。该文基于我国灾害条件下高密度人口的集体疏散模式,按照灾害区域的具体情况和人口分布,以道路实时速度和路面损毁程度所决定的道路阻抗性作为评判道路疏散能力的依据,构建从危险区域的多集结点到安全区域的多安置点的多层次应急疏散模型,确定集体疏散人员的疏散路径、人数和车辆,实现在最短的时间内的受灾群众整体最优疏散,并以山东省德州发生地震作为实验区,采用Google Map API和C#搭建多层次应急疏散平台,验证了多层次应急疏散模型的可行性。     

灾后临时住房配置的多目标优化模型研究

自然灾害后应急管理部门需要为无家可归的灾民提供合适的临时住房。尽管灾害影响评估软件及系统能帮助应急决策人员估计自然灾害后预期的无家可归的家庭数量,但是它们不能辨识最优的灾后临时住房。该文首先从灾民的就业和教育机会、分配的临时住房和灾民偏好住房间的距离、临时住房的质量和交付时间、临时住房的安全性、临时住房接近公共服务设施的程度和总公共支出六个方面归纳了灾后临时住房优选的指标,并给出了各项指标的评价标准;然后以社会经济破坏最小和总公共支出最小为优化目标,建立了灾后临时住房的多目标优化模型;最后应用实例验证了模型的适用性和可行性。     

计算机仿真方法在人群疏散影响参数研究中的应用

建筑物中的人群疏散受到灾场环境、建筑结构以及人员本身等诸多因素的共同影响,明确这些因素的影响机理与程度对人群的疏散安全具有重要意义.借助仿真软件buildingEXODUS,以某地铁车站为例,定量地研究了人员行走速度等参数对人群平均等待时间和人群平均行走时间的影响.结果表明:不同参数对人群疏散的影响存在着差别.即使是相同的参数,在不同类型的建筑中,其影响程度也可能发生变化.在此基础上,明确了出口涌流能力、疏散人数、行走速度和疏散准备时间四个对整体疏散时间影响显著的参数,通过对上述参数的控制,可以提高人群疏散的安全可靠性.     

面向多受灾点多出口应急疏散的动态控制流算法研究

针对突发灾害事件发生时大型人群聚集场所的受灾特点,以所有人员全部疏散完毕的时间最小为目标,研究了受灾点有优先顺序和疏散路线及节点有容量限制下的多受灾点多出口应急疏散问题。基于疏散路段流量尽可能充分利用的思想,提出了一种动态控制流算法,该算法将应急疏散问题划分成两个阶段。第一阶段引入饱和流量和实际流量的概念,计算出每个受灾点的最优短路集合及实际流量;第二阶段对各受灾点同时进行动态疏散,在疏散过程中记录每条路段的实时流量,按照受灾点的优先顺序实时地处理流量冲突,使得冲突路段的流量都能够被充分利用,从而得出满意的疏散方案。最后,采用数值算例验证了动态控制流算法的有效性和可行性。     

突发事件下大规模人员临时应急避难所的选址研究

近年来突发事件时有发生,人员紧急疏散显得日益重要。本文研究了突发事件下人员临时应急避难所的选址问题,基于单一指派约束和容量约束的设施选址问题(SSCFLP)研究基础,假设疏散时间随机和选址网络随机,考虑一个星期和一天中不同时间段疏散人员数量不同的现时情况,建立临时应急避难所选址模型,并采用启发式算法进行求解,确定临时应急避难所的数量和位置,并通过实例验证模型的可靠性。将人群聚集在临时应急避难所等待救援,可以节约救援车辆等资源,大幅减少疏散时间,提高人员应急疏散效率。     

Predicting self-evacuation in Australian bushfire

Australian bushfire safety policy does not require mandatory evacuation from bushfire as practiced in North America and other jurisdictions. Australian householders confronted with a bushfire threat must decide whether they remain and defend their property or evacuate. A better understanding of factors that influence householders’ decisions to self-evacuate can inform bushfire safety policy. Studies have identified variables that motivate evacuation from various hazards, including wildfire, but factors shaping the decision processes are not well understood. The Protective Action Decision Model (PADM) provided a theoretical framework of factors influencing protective response to hazard to analyse the actions of householders affected by two bushfires. Three factors that predict self-evacuation were identified: the perception that evacuation is effective in protecting personal safety; the receipt of official warnings; and perceived threat to property. These findings reinforce the importance of increasing householder awareness and sensitivity to the danger posed by bushfire; the adequacy of people’s bushfire preparedness; the effectiveness of early evacuation in protecting personal safety; and the potential persuasiveness of accurate, relevant and timely official warning messages in influencing safe evacuation from bushfire.     

ENHANCING EVACUATION WARNING COMPLIANCE: SUGGESTIONS FOREMERGENCY PLANNING*

This review of incentives to evacuate is meaningful largely in the context of planning for and managing the consequences of the impact of riverine floods. Of course, incentives do not constitute an emergency plan. At best, they should be seen as suggestions for structuring some elements of a plan. Furthermore, the enumeration of incentives presented here is meant to be suggestive rather than exhaustive. A primary objective of this paper has been to underscore the importance of advance planning in coping with hazards and to argue that, even though limited, existing research can be productively used in the planning process. The incentives described here are based upon or drawn from empirical research on people's performance under flood disaster conditions. This reflects the view that it is important to build emergency planning around people's known reaction patterns. Too often emergency plans which are administratively devised turn out to be based upon misconceptions of how people react (cf. Drabek and Stephenson, 1971, p. 202; Dynes et al., 1972, p. 31) and, therefore, potentially create more difficulties than they solve. One must be cautioned, however, that although our data indicate that people say they would support the idea of various evacuation incentives examined here, these are attitudinal data and not performance data. Thus, the real test of evacuation incentives lies in their implementation and in evaluation data on pilot programs which, unfortunately, do not presently exist. The outlook for the feasibility of developing and utilizing evacuation incentives appears to be positive, though, judging from responses to our interviews. In the final analysis, it would appear to be wise to develop emergency plans which guide and channel citizen actions into complementary and productive protection behavior patterns. The present discussion of incentives to evacuate is intended to encourage data-based emergency planning.     

Community resilience and volcano hazard: the eruption of Tungurahua and evacuation of the faldas in Ecuador

Official response to explosive volcano hazards usually involves evacuation of local inhabitants to safe shelters. Enforcement is often difficult and problems can be exacerbated when major eruptions do not ensue. Families are deprived of livelihoods and pressure to return to hazardous areas builds. Concomitantly, prevailing socio-economic and political conditions limit activities and can influence vulnerability. This paper addresses these issues, examining an ongoing volcano hazard (Tungurahua) in Ecuador where contextual realities significantly constrain responses. Fieldwork involved interviewing government officials, selecting focus groups and conducting surveys of evacuees in four locations: a temporary shelter, a permanent resettlement, with returnees and with a control group. Differences in perceptions of risk and health conditions, and in the potential for economic recovery were found among groups with different evacuation experiences. The long-term goal is to develop a model of community resilience in long-term stress environments.     

基于系统动力学模型的影剧院人员疏散策略

随着社会的发展,人们对生命的重视程度日益增强,大型公共场所临灾情况下人员疏散问题的研究也越来越有实际意义.分析以往影剧院火灾事故可以发现,不正确的疏散逃生行为所引起的通道堵塞,是导致人员大量伤亡的一个主要原因.根据系统动力学原理,应用STELLA系统软件,建立了基于粗网络模型的人员疏散模型.以影剧院发生火灾为例,分析了采取不同疏散策略所产生的避难效果差异,找出了最佳的疏散策略.所提研究方法和建立的模型,对于合理设计疏散路线和优化建筑物的出口与通道结构具有一定的实用价值.     

Factors affecting the evacuation decisions of coastal households during Cyclone Aila in Bangladesh

Despite sincere efforts by concerned agencies and recent improvements in hazard warnings, thousands of at-risk people did not evacuate during Aila, a category-I tropical cyclone that struck southwestern coastal Bangladesh in 2009. This study investigated the responses of the people affected by Aila to cyclone warnings and associated evacuation orders, and unveiled behavioural aspects that explain why they did or did not comply with the evacuation orders. Utilising the primary data collected from 420 households living in the severely affected coastal sub-district Koyra, located in Khulna District, this study found that although more than 97% of the households had received cyclone warnings and evacuation orders before Aila's landfall, only around 26% had evacuated. We also examined this study's empirical findings for factors that had dissuaded people from complying with the evacuation orders. Relevant test statistics along with results from principal component analysis suggested that the significant and systematic absenteeism of households from disaster preparedness training appears to be one of the key determinants that affected their evacuation decisions, along with factors related to warning messages, the attributes of cyclone shelters, risk perception, and socioeconomic aspects. A number of recommendations are also presented in this study for people at risk to improve their evacuation rates in future emergencies, not only to save their own lives but also to save their livestock.     

基于GIS和OREMS的洪灾避难系统

面对突发的灾害,人类采取避难转移的方式来减少生命和财产的损失。大范围的人口转移是一个十分复杂的过程,必须有合理的计划和有效地利用现有的交通设施。提出了基于GIS和OREMS的洪灾避难系统来模拟洪灾的避难转移过程。根据洪灾危险区的统计资料,应用基于GIS的风暴潮洪灾风险系统分析洪灾淹没范围、避难区域的人口分布、路网结构,使用OREMS避难交通模型模拟避难过程。以长兴岛为例进行洪灾避难交通模拟,得到避难耗费时间,路网拥堵路段,并且在分析模拟结果的基础上对避难计划进行优化。     

某综合楼钢结构抗火安全设计与评估(Ⅰ) --人员疏散及建筑火灾温度场分析

随着建筑设计理念及建筑技术的发展,很多新型建筑超出了当前防火规范所涉及的范围,这类建筑就要根据性能化思想来进行防火设计。某综合楼为一高层钢结构建筑,采用先进的建筑理念,在建筑内部设置了很多的大空间。基于这一新颖的结构,采用性能化方法对其进行了人员疏散时间、空气升温及结构构件升温等方面的研究。其中人员疏散通过计算机疏散模型进行了研究,大空间火灾升温采用FDS软件进行了模拟,构件升温采用AN SY S软件进行了分析。结合《规范》要求,确定了火灾时合理的人员疏散时间、空气升温及构件升温。     

大型公共场所人群拥挤踩踏事故机理初探

近年来的事故灾害统计分析表明人群拥挤踩踏事故已逐步成为大型公共聚集场所的主要人为事故灾害类型之一.与火灾等常见人为事故灾害不同,人群拥挤踩踏事故的发生极其突然,社会影响重大.从人群拥挤踩踏事故的致因机理及承载体人群的运动规律开展相关研究,基于风险理论、事故突变等理论方法提出了人群拥挤踩踏事故风险(四阶段)理论,并构建了理论模型,对理论模型中的参数求解进行了阐述.人群拥挤踩踏事故风险理论研究可以为揭示人群聚集相关事故成因机制及形成演变规律提供一些有益的尝试及参考,其中的相关理论模型可供大型建筑(如奥运赛场)性能化设计、人群安全疏散及管理等工作参考.     

大型公共场所人员疏散模型研究--考虑个体特性和从众行为

在引入元胞自动机概念的基础上,模拟分析了紧急情况下人员的疏散行为,并提出了一个新的疏散模型.该模型考虑了人员的个体差异和从众行为,并重点分析了各种情况下从众行为对疏散行为和疏散时间的影响.结果表明,从众行为与疏散场所中的人员密度、视野范围大小等都有很大关系,一般而言,从众行为将延缓人员疏散的时间.     

从人员疏散的角度研究公路隧道的横通道间距

隧道的横通道作为人员疏散的安全地带,其间距的设置在人员安全疏散中是至关重要的。以雪峰山隧道为工程实例,从人员安全疏散的观点出发,阐述了一种计算横通道间距的方法,并简述了方法的应用。首先根据特长隧道火灾特点,模拟分析特长隧道四种不同火灾场景下的典型自然疏散过程,并运用火灾模拟软件FDS4.0计算四种火灾场景在不同横通道间距情况下的危险时间,然后与相应的包含人员疏散行为特征的疏散时间相比较,得出该隧道最适宜的横通道间距为270m,并分析其经济性。其方法和结论可为特长隧道消防系统的设计、紧急疏散方案和引导指挥体系的建立提供理论依据。