A Research On Storage Allocation In The Slot Multiplexed Container Yard

With the rapid growth of container traffic, the container yard use more and more are also increasing. In order to be able to ease the yard bottlenecks of stations, ports and logistics center, it is imminent to improve the operational efficiency of container yard.Generally speaking, there are two stacking modes in container yards. One is stacked in accordance with the attribute such as the container type, the consignee or consignor, the whereabouts and so on. And the other is stacked together with the messy consignee or consignor and the whereabouts, only separated in accordance with the container type.The first way is simple in management and high efficiency without relocation operations. It applies to the spacious yard or bulk cargo containers with the simple consignee or consignor and the simple whereabouts,which is used more commonly in the railway station.The second way is complex in management. Its operating efficiency is lower than the first way,with frequent relocations. It applies to the tension yard and Scattered cargo containers with the complex consignee or consignor and the complex whereabouts.The second way is worthy of further study because of conforming to reality. So this paper studys how to allocate slots reasonably when the departure and arrival of the container is random, it aims at avoiding or minimizing relocation operations, and improving the efficiency of yard operations.Firstly, the paper introduces the basic concepts of the yard and mathematical theories and gives a brief overview about the storage allocation problem and related issues. Secondly, With the adequate theoretical preparation, this paper sets up the models M1and Q1from the sides of laying and fetching containers.The models M1and Q1describe the storage allocation problem preliminarily. But there are some insufficients by analysising the solution of models. So it sets up the new modes M2and Q2to improve M1and Q1. In order to describe the problem more comprehensively, the paper sets up the laying-fetching model M-Q from the overall yard perspective. All in all, this paper discribles the problem about storage allocation from different perspectives. In order to solve the established models, this paper designes the algorithm about searching the block for a container and the algorithm about laying and fetching containers. And the paper introduces the concept of the random total order, closure, etc so that it improves the algorithm about laying and fetching containers. Thus it can ease the Old-Box problem. Considering the phenomenon of yard fragments for the tension-type yard, it designs a algorithm to collate yard fragments that can make the yard restore a healthy and orderly state as soon as possible. That can assist the following-up operation in going on smoothly. Finally, On the basis of the models and algorithms in this paper, this paper conducts detailed numerical examples for several typical palletizing states. At the same time, it uses the algorithm4.4to collate yard fragments and gives the detailed algorithm steps and results.Through detailed numerical examples, the results reflectes the core idea of models and algorithms.That’s containers with the same property should be palletized together as much as possible;when containers with different properties have to be overlapped, the classifications of Laminated heterogeneous containers are as little as possible. Simultaneously, Examples also illustrates the feasibility and validity of the algorithms in the paper.