Optimization Of Train Handling Operations For Sea-rail Intermodal Container Transportation In Seaport Railway Terminals

Prompting the development of railway container transportation and establishing a hinterland multi-modal freight transportation network based on the railway lines have become the main development directions for China's freight transportation system,which,actually,shows an evident gap between the world-advanced level.In addition to the reason of the administrative system,the main reason leading to this gap lies in that the railway transportation network is not well cooperated with maritime terminals,both spatially and operationally.To be specific,as the railway lines are not introduced into port areas for most container terminals,a transshipment operation between railway terminal and container port conducted by trucks is needed,which,to some extent,makes the organization process more complicated and could increase the operation cost.To handle this issue,introducing railway lines into container terminals has been listed as a main task in the development of multi-modal transportation system.Though this action could help to address the issue of “last-mile”,it would also lead to some new problems.More operations are needed in the port area,and thus the decisions are more complicated.When the railway lines are introduced,terminal operators need to determine when and how to load and unload trains with limited resources while considering the organization requirements of railway trains,which makes the seaport railway terminal different from the tradition seaport terminal.In this thesis,we are going to research the following topics related to the train handling operations:(1)The framework of the joint optimization theory for train handling operations involved seaport railway terminal.Though the short-distance transshipment between ports and railway terminals could be avoided by introducing the railway lines into the port area,it could also complicate the terminal operations significantly.In this study,the terminal operations involved in the container terminal with and without on-dock rails are compared,and the influences caused by the on-dock rails are analyzed.Based on the analysis,we select the seaport railway terminal with on-dock rails as the main research object.Then,the operational objective,operation objects,as well as the operation process of intermodal containers are analyzed,and the key operation process involved in this process is defined.Furthermore,the a joint optimization framework for train handling operations involved seaport railway terminal is proposed,in which both tactical planning problems and operational planning problems are included.(2)The optimization of the transfer plan in the mode of railway-maritime collaboration with the consideration of direct-transshipment.In this section,a tactical planning problem with the aim of coordinating the capacity supply and transport demand is studied.A mixed-integer programming model is proposed to jointly optimize the train schedule template,transshipment plan of intermodal containers,and discharging plan of vessels with the objective of minimizing the dwell time of container while maximizing the proportion of the directly-transshipped containers.The trains are assumed to be block trains with predetermined latest leaving time and running direction,and the direct-transshipment mode is applied when transferring import containers.In order to solve the model effectively,a tailored rolling horizon approach with a backtracking strategy and adaptive horizon span is proposed.Then,the influence of handling capacity,operation capacity of shunting engines,and length of time window are influenced based on the results of numerical experiments.(3)The optimization of the transfer plan based on “go-when-full” policy and pre-determined discharging plan.The train schedule template and transshipment plan of intermodal containers are jointly optimized with the objective of minimizing the total operation cost,in which the influences of closing time,trains' arrival time,and the handling capacity is considered.In this research,we assume that the discharging plan of vessels is pre-determined,and the trains do not have a given running direction and leaving time requirement.A mixedinteger model is proposed to describe the problem quantitively.To solve the model effectively,we further enhance the model using valid inequalities.Moreover,we proved that some integer variables can be relaxed to be continuous when some conditions are met.The influence of the unit cost is analyzed based on the results of numerical experiments.(4)The integrated scheduling of several handling equipment in the railway handling area of seaport railway terminals.The scheduling plan of three types of handling equipment,namely rail-mounted gantry cranes,internal trucks,and reach stackers,involved in the handling operation of trains are jointly optimized with the objective of minimizing the makespan as well as the waiting time of handling equipment.The genetic algorithm with the rule of the first available machine is proposed to solve the problem efficiently,and the influence of different handling equipment schemes are analyzed.