Research On Half Open Routing Optimization For Hazardous Materials Transportation

Benefit from the rapid development of the petrochemical industry,hazardous materials have been extensively applied in industry,agriculture,manufacturing,national defense,medicine and people’s daily life.Hazardous materials have toxic,corrosive,explosive,combustion and other properties,once an accident occurs in the two links of storage and transportation,it will cause very serious consequences such as personnel casualty,asset damage,environment disruption,etc.In addition,in logistics transportation,based on actual scenario considerations,companies will adopt the half open transportation mode,that is,vehicles can choose any depot to stop after completing their transportation tasks to reduce cost and improve efficiency.In this dissertation,from the perspective of reducing risk and cost of hazardous materials storage and transportation links,combined with actual transportation scenarios,the half open route optimization problem for hazardous materials transportation is studied in depth.The main research work of this dissertation is as follows:(1)The multi-depot vehicle routing optimization problem for hazardous materials under half open is studied.A dynamic transport risk model and a bi-objective mixed integer programming model under half open are constructed by considering the influence of vehicle loading,multiple vehicle types and hazardous materials categories on transportation risk and transportation cost.A genetic algorithm based on?-constraint method is designed,and numerical examples are given to verify the validity of models.Calculation results show that average transportation risk and average transportation cost of the half open vehicle routing optimization model can be reduced by 3.02% and 2.40% respectively,meanwhile,the Pareto optimal solutions can provide a variety of routing optimization schemes for decision makers.(2)The multi-depot location-routing optimization problem for hazardous materials under half open is studied.Combining the location of hazardous materials facilities,considering depot location risk and depot rental cost,on the basis of the dynamic transportation risk model,a location-routing system risk model and a bi-objective mixed integer programming model under half open are constructed respectively.An improved genetic algorithm based on ?-constraint method and a non-dominated sorting genetic algorithm with elite strategy(NSGA-II)are designed,and numerical examples are given to verify the validity of models and algorithms.Calculation results show that the half open location-routing optimization model can reduce the system risk within the acceptable range of system cost change.This dissertation find that considering the half open vehicle transportation mode can effectively reduce risk of hazardous materials storage and transportation links,in line with the goal of hazardous materials safety management,and research findings have a certain guiding significance for hazardous materials enterprises and related management departments.