A tabu search algorithm to solve the integrated planning of container on an inter-terminal network connected with a hinterland rail network

Transport demand for containers has been increasing for decades, which places pressure on road transport. As a result, rail transport is stimulated to provide better intermodal freight transport services. This paper investigates mathematical models for the planning of container movements in a port area, integrating the inter-terminal transport of containers (ITT, within the port area) with the rail freight formation and transport process (towards the hinterland). An integer linear programming model is used to formulate the container transport across operations at container terminals, the network interconnecting them, railway yards and the railway networks towards the hinterland. A tabu search algorithm is proposed to solve the problem. The practical applicability of the algorithm is tested in a realistic infrastructure case and different demand scenarios. Our results show the degree by which internal (ITT) and external (hinterland) transport processes interact, and the potential for improvement of overall operations when the integrated optimization proposed is used. Instead, if the planning of containers in the ITT system is optimized as a stand-alone problem, the railway terminals may suffer from longer delay times or additional train cancellations. When planning the transport of 4060 TEU containers within one day, the benefits of the ITT planning without considering railway operations account for 17% ITT cost reduction but 93% railway operational cost growth, while the benefits of integrating ITT and railway account for a reduction of 20% in ITT cost and 44% in railway operational costs.     

The multi-port berth allocation problem with speed optimization and emission considerations

The container shipping industry faces many interrelated challenges and opportunities, as its role in the global trading system has become increasingly important over the last decades. On the one side, collaboration between port terminals and shipping liners can lead to costs savings and help achieve a sustainable supply chain, and on the other side, the optimization of operations and sailing times leads to reductions in bunker consumption and, thus, to fuel cost and air emissions reductions. To that effect, there is an increasing need to address the integration opportunities and environmental issues related to container shipping through optimization. This paper focuses on the well known Berth Allocation Problem (BAP), an optimization problem assigning berthing times and positions to vessels in container terminals. We introduce a novel mathematical formulation that extends the classical BAP to cover multiple ports in a shipping network under the assumption of strong cooperation between shipping lines and terminals. Speed is optimized on all sailing legs between ports, demonstrating the effect of speed optimization in reducing the total time of the operation, as well as total fuel consumption and emissions. Furthermore, the model implementation shows that an accurate speed discretization can result in far better economic and environmental results.     

基于系统动力学的枢纽换乘系统运能匹配研究

换乘设施规划布局对枢纽换乘效率至关重要。利用系统动力学的理论及方法,从系统性角度研究枢纽设施与交通需求匹配关系,确定构建枢纽内部换乘系统运能匹配系统动力学模型的一般方法。运用该方法构建枢纽内部铁路换乘城市轨道交通运能匹配模型。以北京西站铁路换乘地铁系统相关数据进行实例验证,发现安检设施为铁路换乘地铁系统的运营瓶颈点,经验证发现模型误差在3%以内。针对系统运营瓶颈点提出相应改善措施,运用该模型进行仿真发现,适当增加安检机、扶梯、楼梯以及检票机的数量,能够很大程度上提升系统客流运营的效率。     

时空紧约束的大都市圈轨道交通规划研究

进入大都市圈快速发展阶段后,中国大城市交通发展普遍面临空间和时间紧约束。轨道交通由此成为大都市圈时空组织的战略选择,构建以轨道交通为主体、多层次中低运量公共交通为基础的公共交通体系成为共识。面对大都市圈集聚发展、近中期通勤圈可能继续外扩等发展前景,提出轨道交通线网规划应重点围绕缩短出行时间和提高覆盖率等时空组织要求。进而通过差别化的空间政策和交通政策,耦合轨道交通枢纽与城市中心体系,促进轨道交通轴带功能集聚。最后,强调以轨道交通为核心,加强一体化衔接规划和城市交通综合治理,主动引导城市空间有序拓展,实现轨道交通与大都市圈协同发展。     

海洋环境下在役钢筋混凝土构件抗弯可靠度的预估方法

在腐蚀介质作用下,在役钢筋混凝土构件抗弯承载能力逐步衰减、安全可靠性不断降低。基于海洋环境下钢筋混凝土受弯构件力学性能的劣化规律,提出了在役钢筋混凝土构件抗弯可靠度的预估方法,可为海洋环境下在役钢筋混凝土结构耐久性评估及维修决策提供理论依据。     

农村公路建设成本控制方法

通过对农村公路建设过程中旧路面利用、合理控制路基高度、就近利用路面材料等方面进行分析探讨,以求达到合理降低农村公路建设成本的目的。     

加强既有线牵引供电调度应急指挥能力的探讨

铁路第六次大提速后,高速动车组大量开行,传统的牵引供电事故指挥方式已不能满足当前发展的需要.本文针对牵引供电系统的管理现状,就既有线提速改造后如何增强电气化区段应急指挥能力进行了探讨.     

京郑既有线CTCS2级信号系统方案研究

分析了京郑线信号系统既有低频信息的特殊性,提出了在京郑线提速200km/h,车载设备能够兼容其他提速200km/h线路的CTCS2解决方案,工程可实施性强。     

新建石太客运专线、构筑客货运输大通道

本文从石太线运输能力现状分析入手,结合我国客运网规划阐述了新建石太客运专线的必要性、迫切性。对本线采用的主要技术标准进行了分析、论证,结合通道运输性质、枢纽总图规划、沿线地质情况研究了枢纽引入方案和区间走向方案,并对本线预期经济效益进行了评价。     

既有铁路包西线延安北至新丰镇段黄陵车站改建方案研究

既有线包西线延安北至新丰镇段,是铁路网中“八纵八横”运输主通道“包柳通道”的重要组成部分,由于目前该既有线路标准低,站后运营设备从简配备及陈旧、落后,已成为“包柳通道”中的“瓶颈”,必须对该线进行扩能改造。而既有黄陵车站能力非常紧张,站线能力不配套.黄陵车站改建方案的成败与否,直接影响到该线扩能改造工程的效果,因此,本文就车站改建方案作了综合分析研究。