Research On Optimization Of Container Port Distribution System Based On Service Network Design

It is still prominent problem of unreasonable port collection and distribution structure with the increasing throughput of container ports.The important measures to optimize the port collection and distribution system is to increase the proportion of railway and sea-rail intermodal transportation for the volume of collection and distribution in ports.Therefore,in the national "Thirteenth Five-Year" Port Collection and Distribution System Construction Plan and the "14th Five-Year" Comprehensive Transportation Development Plan,it is proposed that the focus will be to break through the "last mile" of railways entering the port,and to improve the port and railway distribution.It will speed up the construction of the port collection and distribution system,and provide support and guarantee for the promotion of port transformation and upgrading,the development of multimodal transport,and the promotion of the supplyside structural reform of transportation.This paper takes container ports as the object,realizes the transfer from road distribution to railway distribution through the optimization of port collection and distribution plan,and studies the optimization of port collection and distribution system.The main research contents of this paper are as follows:In chapter 1,after collecting and consulting existing related documents,it is to construct a container port distribution service network under road transportation,railway transportation and its intermodal transportation,and consider train timetable,transportation capacity constraints,and the latest arrival time of the goods constraints for a suitable plan for the distribution of goods at the port.In chapter 2,based on the concept of the container port distribution system,it is introduced for the distribution network,transportation facilities and equipment and the management of evacuation,which lays the theoretical foundation for this article.In chapter 3,for research on the container port’s evacuation network,it starts from the container port’s evacuation physical network,combined with the hub-and-spoke network structure.Then the characteristics of the container port hub-and-spoke network structure are described,and the container port distribution service network is constructed according to the time-space network model.It is to reflect the cargo transportation information as well as road and railway transportation information by using the spatiotemporal nodes and spatiotemporal arcs,which lays the foundation for the following function definition based on the spatiotemporal arc in the service network.In chapter 4,it is studied and set for the cost functions and time functions of various spatiotemporal arcs in the container port distribution service network.On this basis,the optimization model of the container port distribution system is constructed with the optimization goal of the total cost minimization,the flow balance constraint,the transportation capacity constraint,the transfer frequency constraint,and the latest arrival time constraint.In chapter 5,the Astar pathfinding search algorithm and the Lagrangian relaxation algorithm are used to solve the model,and at the same time performs Lagrangian relaxation and sub-gradient processing on the model in this paper,laying the foundation of the algorithm for solving the calculation example.In chapter 6,Taking Ningbo-Zhoushan Port as an example,build a Ningbo Port’s distribution service network based on the information of cargo transportation tasks,railway and road transportation,and use the proposed container port distribution system optimization model to solve the case.A comparative analysis is made of the results of the distribution plan under the condition of charging carbon tax and not charging carbon tax on road transportation.The above analysis can provide reference for the optimization of container port transportation system.