静态单点多目标危险品道路运输路径优化

为控制危险品运输对环境和居民造成的影响,基于不同运输决策者的路径选择要求,建立有关静态单点多目标约束条件下危险品道路运输路径优化的多个模型。分析危险品事故率影响范围、人口暴露、环境破坏和综合后果风险,并以距离、成本及风险最小化为目标,设计运输路径优化算法,运用灰色关联分析法(GRA)选出与"绝对最优路线"关联度最大的次优路线;最后以国内某公司的苯乙烯运输为例,验证模型和算法。结果表明,模型和算法适于求解危险品运输路径的优化问题,能得到运输时间较短、成本较低、对人和环境危害较小的最优路径。     

危险品道路安全运输路径优化方法探讨

危险品道路运输量逐年增加,对人类安全健康的危害的风险正在扩大和加深,一旦发生事故,其后果极为严重。笔者从人-机-环境角度分析了危险品道路运输系统的组成要素,基于对运输网、运输风险源、后果影响区域3个层次辨识,分析运输过程中的风险影响因素,提出危险品道路运输路径优化选择的一般方法;并给出危险品道路运输线风险源的可接受个人风险和社会风险标准;探讨了危险品运输约束最优化选线模型。路径优化选择可减少运输沿线影响人员风险和事故概率,优化影响人员风险与运输效率冲突问题,为政府监管部门与危险品运输企业提供了安全管理的基本决策依据。     

基于相异路径的危险品运输车辆调度

为有效降低多车同时运输危险品时的潜在风险,针对危险品运输网络中2点间相异路径上多车运输问题,提出车辆安全出发时间间隔计算方法,通过路径选择和车辆调配,建立相异路径上多车同时运输车辆调度数学模型,并设计基于非支配排序遗传算法(NSGA-II)的多目标优化算法求解。以8个节点13条边的危险品运输网络中运输10车危险品为例,根据所提方法获得单次运输风险约束条件的运输方案13种,运输总风险约束条件下运输方案15种,对比不同风险约束下的运输风险、运输距离和运输时间。结果表明：相比于运输总风险约束,单次运输风险约束更严格,适合道路管理者筛选安全的运输路径,而运输总风险约束适合承运企业在车辆调度时作出决策。     

基于点危险源的危险品运输路径优化研究

为合理选择危险品运输路径,降低危险品运输事故造成的损失,使道路危险品运输风险评价更符合实际情况,建立点危险源风险评价模型。模型综合考虑了运输时间和季节情况影响因子,在准确估算危险品泄漏事故毒害区域面积和后果损失的基础上,结合传统风险评价模型与最大最小模型进行求解。最后通过算例分析,检验该模型的实际运用,通过与传统求和方式所得的最优运输路径的对比,反映2种方式所求得的最优运输路径并不相同,同时也表明,用所建模型求得的运输路径风险值有更高的精确性。计算结果表明:该模型求得的某条运输路径的风险值等于该路径上风险值最大的路段的风险值,而不是该路径上所有路段的风险值之和。     

危险品道路运输多目标路径优化方法研究

道路危险品运输路径优化是提高危险品运输安全的一项重要措施。通过对国内外文献的分析研究，本文提出了危险品道路运输路径优化的数学模型，该模型首先求出单项目标的最优解，然后找出每项目标的实际值尽可能接近各自单项的最优值。本文也建立了包括路线长度、时间、费用、路线风险、敏感目标人数在内的危险品道路运输目标体系，并给出危险品运输路线选择决策的程序，为政府相关部门进行路线选择提供决策依据。     

不确定需求下危险品运输路径问题的多目标优化

为评估危险品运输路线的稳定性与可靠性,设计动态运输网络,构建以道路安全指数、总运输成本与目标函数期望值的最优组合为目标的随机优化模型。考虑运输网中发生交通拥堵或封路的情形,探究危险品运输终端的不确定性需求对运输总成本与道路安全的影响;针对危险品运输的特殊性与复杂性,将人口中心到附近路段的最短距离与中心的人口数的比值设为道路安全指数;采用基于改进的粒子群算法(PSO)求解模型算例,能得到不同封路情况下不同目标期望的危险品运输路线。结果表明,不确定需求的样本差异对路径的运输稳定性有影响。     

危险品道路运输过程风险管理体系探讨

危险品道路运输是一个复杂的系统,风险管理涉及危险品运输规划和事故应急响应。本文介绍了现有的危险品运输风险管理模式和基本管理原则,基于运输风险评估、运输路径优化、应急单位优化选址和选线、人员疏散管理以及事件决策管理等构建了危险品道路运输过程风险管理体系,阐述了系统基本要素之间的相互关系。危险品道路运输过程风险管理是一个持续改进的结构化过程风险管理体系,有助于减少危险品运输事故概率和降低运输沿线影响人员风险,为政府监管部门和危险品生产经营单位的运输安全管理、优化选线以及应急救援等工作提供技术依据,合理规划危险品运输系统。     

危险品道路运输风险评价与优化选线的研究进展

危险品道路运输的风险评价与优化选线是对其进行安全管理与科学化决策的基础和重要依据,也是减少危险品运输事故概率与降低运输沿线影响人员风险的重要措施.通过对国内外危险品道路运输风险评价与优化选线研究以及相关技术与软件的发展状况进行详细评述,总结了常用的风险评价模型、选线标准以及优化选线方法,并给出了一些国家的个人风险和单位运输距离(通常为1 km)社会风险的可接受标准.最后,对我国的危险品道路运输安全管理提出了对策与建议.     

级联失效特性下的危险品运输路径选择研究

基于复杂网络的级联失效特性,构建危险品运输网络的级联失效模型,提出用路段重要度来度量某条路段上发生危险品事故后引起网络其他路段失效的规模。以路径风险最小化和路径总重要度最小化为目标,建立危险品运输路径的多目标决策模型,并利用标号法进行求解。算例结果表明,危险品运输网络确实存在级联失效现象。选择危险品运输路径时,应尽量避开重要度高的路段,以降低危险品事故对普通道路网络的不良交通影响。     

基于风险的危险品道路运输安全容量研究

为了确定危险品道路运输安全容量,保障危险品道路运输安全,基于风险理念,使用对比研究方法,提出危险品道路运输个人风险基准,建立改进的危险品道路运输定量风险评估模型。结合提出的风险基准,提出危险品运输安全容量确定方法,解决了单一类别和多种类别危险品运输安全容量确定问题。研究结果表明:在某城市化工集聚区的实例应用该方法,能够大幅度降低危险品道路运输潜在生命损失,有助于保障危险品道路运输安全。     

危险货物多式联运路径优化问题的多目标优化算法

为了更为有效地规划与管理危险货物运输,研究在多式联运危险货物时的路径优化问题,同时囊括双目标、多批货物以及货物的送达时间要求和路段的容量限制。以运输和转运过程中的总成本和总风险最小为目标,构建了双目标0-1线性规划模型。集成路径搜索算法和非支配排序规则,设计了基于帕累托分析的多目标优化算法,以获得原问题的非劣路径。算例结果表明,该算法可有效地获得实际问题的一组具有竞争性的非劣解,且相比于单式运输,多式联运危险货物有望同时降低总成本和总风险。     

Multi-objective transportation route optimization for hazardous materials based on GIS

Safety and security are of paramount importance, it is important to optimize and improve the routes of trucks that carry hazardous materials. In this study, we not only ensure the risk in the network, but also consider the transportation cost and the factors such as buildings and emergency facilities around the routes. The Geographic Information System (GIS) is used to quantify the factors on each section in the network. We present an epsilon constrained multi-objective mixed-integer linear programming optimization model to find the robust and stable transportation optimization solutions. At the end, we complete a case analysis of the proposed methodology to determine the motorway segments in Jiangsu province, China and test the above algorithm on the network, which has 144 nodes and 388 sections. The results we get show that the factors of buildings play a very important role in the model, and the multi-objective mixed-integer linear optimization model is reasonable and performs good quality.     

Developing a chaotic pattern of dynamic risk definition for solving hazardous material routing-locating problem

In the case of determining routes and locations for constructing distribution centers on hazardous materials (Hazmat) transportation, risk and cost are considered as the main attributes for developing mathematical models. Since, Hazmat transport risk may be defined as a chaotic factor, using dynamic risk changes the selected routes and optimized locations for constructing distribution centers.In the present paper, an iterative procedure has been proposed to determine the best routes and optimized locations of distribution centers for transporting hazardous materials based on the concept of chaos theory in which hazmat transport risk is defined as a dynamic variable. A mathematical model has been developed for solving Hazmat routing and locating problems, simultaneously. Daily transport risk, defined as a chaotic variable, is iteratively updated using one-dimensional logistic map equation over the time period (year). An experimental road network, consists of eighty nine nodes and one hundred and three two-way edges, has been selected for analytical process and model validation. Results revealed that although different amounts of risk and cost priorities change optimized locations of distribution centers and their associated supplies, but the most frequent set of optimized centers remains independent. Therefore, the proposed procedure is capable to determine the best routes and optimized locations for distributing hazardous materials. While risk is iteratively updated over a specific time period, results show that the main property of chaos theory known as dependency upon initial condition would not be a serious concern for decision makers who are dealing with Hazmat management.     

A transportation network assessment tool for hazardous material cargo routing: Weighing exposure health risks,proximity to vulnerable areas,delay costs and trucking expenses

The inherent risks associated with accidental releases of hazardous materials during transport have drawn attention and concerns in the recent decades. The aim of this study is to propose a tool for evaluation and comparison of the transportation networks which can be used to assess the routing options between origins and destinations of the cargos for their suitability for transporting hazardous material cargos by tanker trucks and to identify routes which provide lower accidental release risks, lower public exposure risks, and offer economical benefits. Each route segment of transportation networks were evaluated using specific criteria which included health risk and cost of delay in case of an accidental release of materials, trucking cost and proximity to vulnerable areas. Since, the health impact of hazardous materials differ depending on the characteristics of the material being transported as well as release quantities and atmospheric conditions; this paper aimed in providing a tool that can be used to estimate the impact radius (for health risks) after accidental release of hazardous materials by taking into account different atmospheric conditions based on the meteorological data and solar elevation angle. The Gaussian air dispersion model paired with ArcGIS using Python programming were employed to estimate the health risk impact zones by considering the meteorological data, and accordingly to analyze road segments for cost impacts (delay and trucking costs), and the proximity to vulnerable areas. The route assessment tool was demonstrated with a case study. The results of this study can efficiently aid decision makers for transportation of hazardous materials.     

有害物品运输的总风险分析

随着工业的发展,有害物品的生产量和运输量均在逐年增加,有害物品对环境和人的危害正在扩大和加深。有害物品运输中的风险是有害物品对于人类、环境和财产等方面威胁的最为重要的组成部分。笔者将有害物品的运输风险分为人口风险、环境风险和财产风险3个部分;在基于事故发生率和事故产生的后果两个方面,分别对人口风险、环境风险和财产风险进行了度量,并给出了风险度量的模型。同时由于各个部分风险度量的量纲并不统一,笔者对3部分风险进行了度量的统一化,获得了总风险的构成,并与传统的单独考虑人口风险的情况进行了对比,为有害物品的运输提供了参考依据。     

危险品运输网络中运输方式和路径优化研究

在危险品运输网络中,往往有多种运输方式和多条运输路径。不同运输方式在不同路径上发生事故所造成的损失不同,不同运输方式的单位运输成本也不同。本文研究了在给定运输起点和终点的情况下,在综合考虑事故所造成的损失最小和运输成本最小的情况下,运输方式和运输路径的选择方法。通过一个仿真例子说明了模型的求解方法和实际效果,并与单一运输方式的方案进行了对比。结果表明考虑运输方式的组合,在一定程度上可以降低危险品运输过程中的社会总期望损失和运输成本。     

基于可能-概率测度转换的危险品运输风险分析

为解决不确定环境下的风险分析问题,针对危险货物运输中风险参数具有不确定性、随机性和模糊性的特点,建立基于概率测度-可能性测度转换原则和模糊逻辑的危险货物运输风险分析方法。首先对具有模糊性的参数直接建立模糊数,对具有随机性的参数建立随机数;接着依据概率测度向可能性测度转换的最优原则,将随机数转换为模糊数;然后根据模糊运算法则进行风险计算和分析。最后通过一个算例验证了模型和算法的有效性。结果表明,提出的方法能处理随机和模糊环境下的风险分析问题,能为风险分析尽可能多地保留不确定性信息,尽可能少地丢失有用信息。     

城市应急物资配送路径支路限流模型研究*

为科学、及时、合理地对城市应急物资进行调度,综合考虑突发事件发生后道路的实时通行状况,通过改变道路交通的交叉口限流以及物资运输路径,以最小化配送时间和成本为目标,构建1套完整的应急交通管制模型,使得所需的应急物资在被要求的最短时间窗内抵达受灾点;利用遗传算法进行编码设计求解模型,并通过仿真分析,设计配送路径的交叉口的支路限流方案;通过实例对所构建模型进行验证。结果表明:在日常道路动态变化情况下,该模型既能实现应急物资配送路径在支路限流下的交通协同方案;又可减少应急物资配送的时间成本,满足最短时间窗要求,使整个应急物流体系更加敏捷可靠。     

HazMat transportation safety assessment: Analysis of a “Viareggio-like” incident in the Netherlands

Relevant safety issues are associated with hazardous materials transportation, especially when transport routes cross populated areas. On March 6th, 2015, a passenger train collided with the last rail car of a freight train in Tilburg, the Netherlands. The last car contained 50 t of liquefied 1,3-butadiene. As a result of the collision, the last car showed deformation; a small leakage occurred but fortunately with no relevant consequences. However, extremely severe consequences could have happened, such as in the rail accident that occurred in Viareggio, Italy in 2009. In this work, the case of Tilburg was firstly outlined and explored by qualitative methods, in order to identify possible realistic final scenarios that could have happened. Second, the potential consequences of the identified scenarios were estimated through conventional integral model for physical effects evaluation. Comparison with the Viareggio case was also shown in order to support the discussion of the results obtained. Finally, lessons learned after the incident, policy making considerations, and indications for the risk mitigation of hazardous materials transportation are given.