Research On The Capacity Calculation And Optimization Of Transshipping System In Railway Port Station

Since "the Belt and the Road" was put forward by president Xi Jinping in 2013,international railway transportation has ushered in an important opportunity for development.The construction of the Silk Road Economic Belt not only provides solid infrastructure guarantee for international railway transportation,but also provides strong policy support for it.The port station is an important node of international railway combined transportation,and it is also an important gateway of the Silk Road Economic Belt in china which is mainly responsible for the handover of international passenger trains,the transportation organization of import and export goods trains,and the transshipment of imported goods.With the gradual implementation of The Belt and Road”,the international logistics demand is increasing steadily,value of import and export of port stations has also grown rapidly.The transshipment task of the port station is becoming more and more heavy,so the capacity of transshipment is crucial to the smooth development of international railway combined transportation.The paper gives a brief overview of the railway port station in China,and sums up the operation and equipment of the railway port station as well as the customs clearance mode at the port station.According to the railway gauge and customs clearance mode,the railway port station is divided into port stations which do not handle the transfer operation under "One port and two inspections,port stations which handle the transfer operation under "One port and two inspections",port stations which handle transfer operation under "Two ports and two inspections".Based on analysis of the operation process of port stations and the design idea of station yard layout,the layout of station and yard of different types of port stations is concluded,which provides reference for layout design of station and yard of new port station.In this paper,the transshipping system of port station is considered as a three tandem queuing system,by analyzing the constitution of queuing system and influence on system capacity with imbalance of service time and the interference of station operation,the three tandem queuing model of port station transshipping system is established.On the basis of researching cumulative counts of arrival trains and departure trains in system and cumulative train counts processed in station operations,the queuing balance model of transshipping system is established and the rational allocation number of facilities is calculated with the constraint conditions of maximum system capacity.After obtaining steady input flow and optimal allocated quantity,it needs to optimize each operation to reduce interference and improve coordination aiming at maximize system capacity.Based on analyzing contents and factors of transshipping lines utilization scheme,the paper builds optimization model and algorithm using time slice which is the simplified description of time intersects.Finally,this paper takes Alashankou station as the example to introduce the station and yard layout,to analyze the freight operation process from broad gauge imported.And according to the station operation detailed rules of Alashankou station,the standard operation time is determined,the transshipping system capacity of both existing and after process optimization are calculated,and the rational allocation number of facilities after optimization is calculated.