基于元胞自动机人员疏散模型的分析研究

元胞自动机广泛应用于社会和自然科学的各个领域,是一种动态模型和通用型的建模方法。将元胞自动机原理运用在建筑物火灾时期人员安全疏散环节中,采用二维元胞法,确定元胞空间和元胞状态,分析研究了具体情况下人员移动行为规则以及危险物扩散对人员行为的影响。设计出了一套基于元胞自动机的人员疏散模型。     

基于连续介质模型的离散元方法中弹簧性质研究

地质体材料的破坏演化过程是地质灾害防治工程中亟待解决的关键科学问题，也是力学的前沿课题。基于连续模型的离散元方法是研究该问题的一种数值方法。用求矩阵特征值的方法，推导基于连续介质模型的离散元方法中三维有限元刚度矩阵转化为离散元弹簧刚度的解析表达式，给出了不同条件下离散元弹簧的取法。研究立方体八节点单元中离散元弹簧的性质，得到棱弹簧、面对角线弹簧以及体对角线弹簧的刚度和方向表达式，给出这些弹簧刚度以及方向与泊松比的关系图。最后，将基于连续介质模型的离散元方法模型与Gusev模型、二维链网模型进行比较。对于泊松比为0．25时的平面应变问题，对于泊松比为1／3时的平面应力问题，基于连续介质模型的离散元方法模型与二维链网模型一致。在块体内部，基于连续介质模型的离散元方法模型与Gusev模型一致。且基于连续介质模型的离散元方法模型能模拟链网模型和Gusev模型都不能模拟边界单元，证明基于连续介质模型的离散元方法模型更具普遍性。     

不规则颗粒及其集合体三维离散元建模方法的改进

以土石混合体中的不规则块石和含石量为40%的土石混合体室内大三轴试样为例,研究了如何针对当前岩土材料建模方法的不足进行改进以建立尽可能真实的不规则颗粒及其集合体的三维离散元模型。为了模拟块石的真实形态特征,明确了块石几何模型建模方法的控制参数及其确定方法,建立了与真实块石球度相同、棱角度相似的三维半真实离散元模型。为了计算模型的体积以用于模型密度优化及颗粒集合体孔隙率的计算,提出了一种三维离散元模型虚拟切片技术,结合数字图像处理技术可快速准确计算块石三维半真实离散元模型的体积。为了使得土石混合体大三轴试样三维离散元模型的密实度与室内试样保持一致并兼顾建模效率,提出了基于拟振动压实法和分层复制法的土石混合体大三轴试样三维离散元建模方法。研究结果表明:所提出的不规则块石几何模型建模方法控制参数较少且可分别对球度和棱角度进行单独控制;当块石离散元模型填充球体数较少时,其体积与对应几何模型体积相差较大,不能直接采用对应几何模型的体积;所建立的土石混合体数值试样与室内试样的细观结构特征基本相同,即块石随机散布于土体基质中。     

面向应急疏散的交通规划与管理研究综述

在应对大范围、大规模的自然灾害与人为突发事件处置过程中,应急疏散发挥着不可替代的重要作用。应急疏散情形下,通常采用交通规划方法来生成疏散指令以保障疏散过程平稳有序,指令内容具体包括疏散人群的出发时间、疏散路径、疏散目的地等。实施交通管理的目的,则是针对应急疏散过程采用各种交通管理措施,以提高出行者对指令的合理服从,并实现疏散效率的最优化。本文首先分析突发事件应急疏散工作机理,从应急交通规划、应急交通管理与疏散主体之间的关系出发,揭示出行者行为对于应急疏散交通规划、交通管理的制约与影响作用。其次,从数学规划、交通仿真以及疏散过程不确定性这三个方面进行建模,论述了应急疏散交通规划研究现状。接着,从交通流预测控制、交通信息服务和车道反向控制等方面,综述了应急疏散交通管理研究现状。最后,对现有应急疏散交通规划和管理研究存在的问题进行评述,同时对未来研究趋势进行展望。     

基于GIS的大型建筑应急疏散救援系统研究

本文介绍了一个基于GIS的大型建筑应急疏散救援系统的结构设计、疏散建模和应用案例等技术内容,通过系统的三层体系结构和功能设计,基于系统的危险源分析和最优应急疏散策略分析,实现人员在疏散通道上的合理分配、组织人员及时疏导阻塞路段等功能,并以可视化、具有真实感的模拟仿真测试对系统功能和应用效果进行仿真验证,以求能够为大型建...     

综合教学楼应急疏散的仿真模拟研究

为研究高校综合教学楼的应急疏散能力,结合某高校综合教学楼的实际情况,利用Pathfinder和FDS对其进行建模并进行模拟。结果表明,相比于只使用教学楼的楼梯,借助体育楼的楼梯,并设定人员路径以及限定人员数量时,人员的疏散时间从870s缩短到283s。在此基础上,提出建议认为,综合教学楼单一功能区的应急疏散可以依靠其他功能区的安全疏散通道,不应锁闭连通各区域的通道以及疏散门;提高人员应急疏散能力、限定人员的数量可以提高综合教学楼的应急疏散的能力。     

基于BIM的施工资源配置仿真模型自动生成及应用

针对目前工程施工资源配置面临的建模过程复杂、效率低等问题,本研究提出一种基于BIM模型数据标准IFC的资源配置离散事件仿真模型自动生成算法。本研究首先构建了基于IFC的进度资源信息模型,通过分析IFC模型与离散事件仿真模型的异同,实现前者向后者的自动转换。并将上述模型与模拟退火算法相结合,开发了模型转换及资源配置离散事件仿真分析软件,应用于实际工程,验证模型自动构建方法的可行性及正确性。结果表明,研究成果可提高仿真建模的速度与准确率,为管理人员快速准确的进度与资源配置、管控提供有力工具。     

综合GAN与CNN的应急疏散快速风险评估方法

针对大型公共场馆疏散风险评估问题,提出一种综合生成对抗网络(GAN)与卷积神经网络(CNN)的应急疏散深度学习评估模型,通过WGAN(Wasserstein GAN)进行数据增强,解决疏散数据不足的问题,并基于CNN,分别采用LeNet以及ResNet两种网络结构进行数据训练.以某大型体育馆为例,应用该方法进行疏散风险...     

天然气泄漏事故现场人员紧急疏散系统开发

对天然气泄漏事故展开原理分析,将其按时间线拆解为泄漏、扩散及疏散三部分。对泄漏模型进行了分析研究,介绍了Gaussian扩散模型、一维模型和CFD方法等扩散模型,并对人员疏散时间的计算机模型和经验公式进行了比较分析。结合天然气泄漏事故现场的应用特点以及快速计算需求,设计开发天然气泄漏事故现场人员紧急疏散系统,为应急预案的制定及应急现场的管理提供帮助。     

特大型体育馆疏散影响因素分析及承赛风险评估

为研究特大型体育馆发生应急事件后人员疏散的影响因素,以青岛市民健身中心体育馆为模拟对象,利用BIM建模软件(Revit)和人员紧急疏散模拟软件Pathfinder,进行全尺寸建模及仿真模拟,并通过灵敏度分析得出影响疏散的主要因素为人数、速度及座位排布,次要因素为人员结构及路线规划。结合德尔菲法、层次分析法确定相关因子权重,采用指标权重评分法建立承赛评估体系,利用此体系进行风险评估,实现BIM技术向运维阶段的应用。     

Developing an evacuation evaluation model for offshore oil and gas platforms using BIM and agent-based model

Accidents on offshore oil and gas platforms (OOGPs) usually cause serious fatalities and financial losses considering the demanding environment where such platforms are located and the complicated topsides structure that the platforms have. Conducting evacuation planning on OOGPs is challenging. Computational tools are considered as a good way to plan evacuation by emergency simulation. However, the complex structure of OOGPs and various evacuation behaviors can weaken the advantages of computational simulation. Therefore, this study develops a simulation model for OOGPs to evaluate different evacuation plans to improve evacuation performance by integrating building information modeling (BIM) technology and agent-based model (ABM). The developed model consists of four parts: evacuation model input, simulation environment modeling, agent definition, and simulation and comparison. Necessary platform information is extracted from BIM and then used to model the simulation environment by integrating matrix model and network model. In addition to essential attributes, environment sensing and dynamic escape path planning functions are developed and assigned to agents in order to improve simulation performance. Total evacuation time for all agents on an offshore platform is used to evaluate the evacuation performance of each simulation. An example OOGP BIM topsides with different emergency scenarios is used to illustrate the developed evacuation evaluation model. The results show that the developed model can accurately simulate evacuation and improve evacuation performance on OOGPs. The developed model is also applicable to other industries such as the architecture, engineering, and construction industry, where there is an increasing demand for evacuation planning and simulation.     

基于神经网络的公共建筑应急疏散风险评估方法

公共建筑空间大、人员密集、水平疏散距离长,在应急情景下的疏散本身存在一定的风险,提出了一种基于深度神经网络(DNN)的应急疏散风险评估方法.给出了DNN预测模型的建立方法,并以某高校体育馆为案例,说明了模型数据获取、模型训练,及模型测试的整个评估过程.结果表明,相较于传统评估方法,该深度学习方法克服了主观性强、对以人为...     

人员密集地下空间应急疏散仿真研究

为了提高地下空间密集人群紧急疏散的科学性安全性,针对轨道交通与地下空间耦合发展的城市形态演化趋势,通过文献梳理与案例分析,开展疏散风险辨识与安全评估理论研究。并利用Anylogic 平台,基于社会力模型和多主体建模方法,构建了某地铁站仿真疏散模型,开展可视化仿真和对照组实验。在站内行人密集程度达到总数1 800 人时开始紧急疏散。实验结果表明,该站现有疏散设施基本满足6 min 内安全疏散的规范要求,但存在行人异质性对疏散瓶颈形成的不利影响,而分区疏散策略有助于缓解瓶颈压力和降低拥堵风险。     

An adaptable microcomputer model for evacuation management

A simulation method is presented which enables a modeler to identify dangerous bottlenecks for emergency building evacuation and to test the sensitivity of occupant exit behavior to evacuation improvement strategies. The modeling method is tested against landmark evacuation data of Pauls and Jones, and used to predict problems and solutions for a complex evacuation situation involving a large university building with multiple exit choices. Some concluding remarks are addressed to a future research agenda for this method.     

城市安全规划之动态疏散与车辆配置策略

在城市安全规划中,人群紧急疏散是其重要内容。在紧急救援的有限时间内,最大化利用应急资源,疏散出最多灾民,是城市人群紧急疏散的第一准则。本文在探讨动态紧急疏散模式的基础上,应用最优化方法,以疏散出人数最多为目标函数,考虑时间因素和多种疏散方式,建立"多对多"动态人群紧急疏散与车辆配置决策模型,并用多维动态规划逆序解法对其进行求解,以获取城市人群紧急疏散与车辆配置的最优策略,拟缓解城市紧急疏散中时间和资源与应急行为的两大矛盾。最后,数值仿真与模拟仿真结果表明:模型和求解方法是有效的。     

消防应急广播系统的性能化设计

文章针对目前消防应急广播系统设计规范和传统设计方法中存在的问题，提出了性能化设计思想和基于安全疏散模型的性能化设计方法，并通过实例分析与比较，从理论上阐述了性能化设计的优越性和在消防安全工程设计中的重要意义。     

Location optimization algorithm for emergency signs in public facilities and its application to a single-floor supermarket

Although emergency signs are believed to play an important role in ensuring public safety in facilities during emergencies, in practice, specific and clear standards for placing emergency signs have not yet been established. This paper developed a heuristic algorithm based on the Lagrangian relaxation algorithm for optimizing emergency sign locations with consideration of light-occlusion effects. A cellular automaton (CA) evacuation model was then introduced, and based on this model, the evacuation efficiency of the optimized locations of emergency signs derived from the algorithm was verified, and was compared with the evacuation efficiencies of the same supermarket without and with existing emergency signs. The results showed that the proposed algorithm greatly enlarged the coverage of emergency signs and improved the evacuation efficiency. It was concluded that the proposed algorithm with consideration of light-occlusion effects is valid for application to the problem of location optimization of emergency signs in single-floor facilities.     

Assessment of ventilation efficiency for emergency situations in subway systems by CFD modeling

The ventilation system is the strategic component of the subway systems when incidents involving heavy smoke occur in tunnels. Consequently, the purpose of this study is to investigate the ventilation efficiency in one of the most severe emergency scenario: train on fire (maximum heat release rate reaching 30 MW due to an ultra-fast fire) and stopped in the tunnel, the incident requiring passenger evacuation. Two ventilation strategies are taken into account: tunnel ventilation fan system (mid-tunnel fan plant located in separate construction) in conjunction with stations mechanical ventilation and end-of-station fan plants in conjunction with stations mechanical ventilation. The analysis is performed using computational fluid dynamics (CFD) modeling. The numerical model proposes an original approach based on the introduction of source terms in conservation equations for energy, carbon monoxide (CO) and carbon dioxide (CO₂), in order to deal with the heat, CO, and CO₂ due to fire. Equations expressing the conservation of CO and CO₂ are specially added to the basic equations governing a turbulent non-isothermal airflow in the CFD model. This method allowed achieving values of velocity, temperature, CO and CO₂ concentrations all over the computational domain. In addition, the modeling and simulation methodology complies faithfully to the real operation of the ventilation systems investigated in normal and emergency (fire) conditions. The results show that both ventilation alternatives taken into account lead to the secure evacuation of passengers all over the simulation time. The evacuation process toward the nearest station is not at all disturbed by too high air velocities, high temperatures or critical CO or CO₂ concentrations.     

Ant Colony Optimization Model for Tsunamis Evacuation Routes

Natural disasters such as earthquakes and tsunamis foster the creation of effective evacuation strategies to prevent the loss of human lives. This article proposes a simulation model to find out optimum evacuation routes, during a tsunami using Ant Colony Optimization (ACO) algorithms. ACO is a discrete optimization algorithm inspired by the ability of ants to establish the shortest path from their nest to a food source, and vice versa, using pheromones. The validation of the model was carried out through two drills, which were conducted in the coastal town of Penco, Chile. This town was strongly affected by an 8.8 Mw earthquake and tsunami over February 2010. The first drill was held with minimum information, leaving the population to act randomly and intuitively. The second drill was carried out with information provided by the model, inducing people to use the optimized routes generated by the ACO algorithm. The results showed that, in case of an emergency, conventional evacuation routes showed longer escape times compared to those produced by the model developed in this research.