Research On Optimization Of Multi-modal And Multi-route Transportation Problem For Hazardous Materials

With the sustained and rapid development of the national economy,chemical companies have developed rapidly in recent years,which has led to a significant increase in the demand for hazardous materials.This has brought unprecedented development opportunities to the hazardous materials transportation industry.Considering the special physical and chemical nature of hazardous materials,once occurring an accident during the transportation,loading and unloading,warehousing,etc.of hazardous materials,not only will it cause damage to the transported materials,vehicles and workers,but also have potential impact on the surrounding residents and environment.Therefore,how to safely,efficiently and cost-effectively transport hazardous materials from the supply to the demand is an important problem.In this thesis,considering the transportation risk and transportation cost in the transportation of hazardous materials,the multi-modal and multi-route transportation problem for hazardous materials under certainty and uncertainty is studied.Based on the actual situation of hazardous materials transportation,the transportation optimization model under certainty and uncertainty is proposed respectively.According to the characteristics of the model,an improved Genetic algorithm is designed for co-optimizing the transportation route and mode,and obtaining a transportation plan with relatively low transportation risks and transportation costs.The main research contents of this thesis are as follows:(1)Based on the analysis of the influencing factors of accidents when transporting hazardous materials on roads and railways,the determination of the probability of occurrence of accidents and the impact of the consequences of accidents,the risk assessment model for hazardous materials transportation is proposed.(2)Considering the particularity of hazardous materials transportation,with the goal of reducing transportation risk and transportation cost,the multi-modal and multi-route hazardous materials transportation optimization model under certainty is proposed,and according to the characteristics of the model,an improved Genetic algorithm is designed,which is mainly reflected in the construction of virtual network,the coding method and the adaptive operation is added in order to avoid the local optimal solution.Finally,the feasibility and effectiveness of the model and algorithm are verified by simple examples.(3)Considering the actual environment of hazardous materials transportation,the transportation of hazardous materials under certainty is only a special case under ideal conditions.Therefore,according to the uncertainty of some parameters(transport time,transportation price,etc.)in the research problem,they are assumed as interval numbers.The multi-modal and multi-route hazardous materials transportation optimization model under uncertainty is proposed and the model is transformed to the deterministic model by the interval ranking method.Finally,the effectiveness of the model and algorithm is verified by the actual case of industrial sulfur transportation,and the sensitivity of the risk factor and objective function weight in the model is analyzed.