A conceptual framework for cooperation in hinterland development between neighbouring seaport authorities

The hinterland of a port is probably the most important aspect in the competition between gateway ports. This paper, starting with a literature overview, shows how the port authority can extend its hinterland with the aim of increasing its attractiveness and, eventually, its throughput. To achieve this, it can be advantageous to cooperate with adjacent port authorities. Together, through cooperation, economies of scale can be realised that facilitate a modal shift away from road to a more efficient and more sustainable transport. This would reduce the cost of transport to/from the hinterland region from/to these ports consequently increasing the attractiveness and the market share of the cooperating ports for this region. The paper describes a conceptual method to identify and quantify the opportunities for cooperation in the hinterland. The framework starts, after some basic transport economic concepts, from (theoretically available) hinterland data to locate regions that are at the edge of the contested hinterland of a port region and results in a methodology that can be used to generate a quantified list of regions where cooperation will make a difference. Using this methodology, port authorities (PAs), of any region where hinterland data are available, can list, together with their neighbours, the regions where to prioritise their efforts.     

高扬程升船机多子结构耦合系统动力特性

采用有限元软件ABAQUS构建了高扬程升船机整体有限元模型,包括地基、塔柱、承船厢、厢内水体、钢丝绳、滑轮组、平衡重和纵横导向机构。通过数值模拟,对升船机整体系统进行了动力特性分析,探讨了地基刚度及承船厢竖向位置对升船机整体结构耦合振动特性的影响。计算结果表明:不考虑地基情况下,结构的振型更为密集,低阶模态中出现了频率为零的振型,运行系统可能发生动力失稳;升船机系统出现的以承船厢为主体的绕轴翻转振型和竖向升降振型将对安全机构的强度和系统的稳定性造成不利影响;承船厢竖向位置由低到高变化时,升船机结构各阶主振型对应频率值呈递减趋势。     

齿轮箱弹性隔振时的推进装置模态分析研究

随着推进主机隔振性能的提升,齿轮箱已成为影响船舶声学性能的重要振源,因此需要采取隔振措施以减小其向船体传递的能量。弹性隔振技术可以改善齿轮箱的振动性能,但是挠性传动部件将导致齿轮箱与推进主机隔振系统之间产生振动耦合,从而增大对推进装置进行模态分析的难度。以某船推进装置为研究对象,基于多刚体动力学理论,推导了计及齿轮箱与推进柴油机隔振系统之间振动耦合特性的推进装置整体隔振系统运动微分方程,并进行了模态分析。结果表明,计及隔振系统之间振动耦合的模态分析结果与两个隔振系统单独进行模态分析的结果存在显著差异,证明了齿轮箱弹性隔振时建立推进装置整体隔振系统分析模型的必要性。最后,对该推进装置的设计和使用进行了评估和建议。     

Flexibility in planning and development of a container terminal: an application of an American-style call option

The prosperity and social progress of developed and developing economies is highly dependent on the existence of efficient transport infrastructure. Nevertheless, current budgetary constraints are jeopardizing the necessary investments in new or existing infrastructure. New models for planning and managing infrastructure are now necessary to overcome the lack of public economic resources available. Port infrastructure is no exception and, due to the vast number of uncertainties involving these projects, it is relevant to maximize the capture of the latent value of flexible options. Incorporating flexibility in these projects, prior to the implementation phase, can be a solution that allows port managers to address future uncertainties and mitigate risk exposure. This paper analyzes the incorporation of flexibility in port planning through the use of an American call option to the physical capacity expansion problem. The rationale is to implement a flexible expansion plan, through options that can be exercised at any given time, that are able to deal with uncertainty in demand. The paper uses a case study – Terminal Container of Ferrol, in Spain – and the results support the hypothesis that imbedded flexibility will robustly increase the net present value of the project.     

基于模态振型的预应力混凝土梁损伤检测

以预应力简支梁为例,通过Ansys有限元模型,分析模态振型在预应力混凝土结构损伤检测中的技术可行性。结果表明:模态振型不仅可以明确地确定结构损伤的存在,而且可以较准确地确定结构损伤的位置。所得结果对于预应力钢筋混凝土梁的健康状况检测具有一定的参考价值。     

基于监测数据的永宁黄河公路大桥动力特性分析

首先介绍频域分解法理论基础和算法实现,然后以永宁黄河公路大桥为背景,介绍结构健康监测系统在实际桥梁中的应用,基于监测数据采用频域分解法进行桥梁结构动力特性分析,将识别结果与成桥荷载试验和理论计算结果进行对比,验证了频域分解用于大跨度桥梁结构运营模态分析的可靠性和有效性,识别结果可以作为桥梁结构安全状态等级划分与评定依据的一项重要指标。     

企业柔性的三维度量

为减少企业柔性度量的复杂性并便于实际应用,综合考虑了企业在应对环境变化时可采取行为的变化范围、企业从一种状态转移到另一种状态作出调整时所表现出的时间性和费用性,以及企业系统对外界状态变化的敏感程度。从范围柔性、反应柔性及状态柔性三个维度对企业柔性进行了度量研究,并进一步推导出企业三维柔性的扩展模型。     

细长海洋立管涡激振动预报模型

涡激振动预报对于深水环境中的细长海洋结构物的设计至关重要.近年来出现的若干经验模型基于圆柱体受追振荡实验数据.文中介绍了细长海洋结构物涡激振动预报工具的发展,进而提出了一种基于圆柱体受迫振荡实验数据的预报模型.与现有的类似模型相比较,该模型更加直接地利用了原始模型实验数据,并且将立管的有限元模态分析并入到响应预报当中,以计及立管物理参数的不均匀特性.利用近期立管模型在阶梯状分布流以及剪切流中的涡激振动响应实验测量数据,验证了该模型的有效性.该模型的计算结果表明,立管的模态振型、模态频率与涡激振动响应高度耦合,并且对于低质量比的情况尤为明显.文中还指出了类似的基于受迫振荡圆柱体实验数据的预报模型存在的缺陷.     

基于能力影响的城市轨道交通跨线列车开行方案研究

城轨跨线运营可减少乘客换乘,提高资源利用率.本文以企业车辆使用成本,列车运营成本和乘客出行成本最小为目标,考虑跨线列车对线路通过能力的影响,以列车发车间隔、满载率、可用车辆数为约束,构建跨线运营模式下的运力配置模型,结合算例提出判定跨线运营模式适用的必要条件.研究表明,实施跨线运营线路需具备一定的冗余能力,其实施效果依赖于跨线客流强度、接轨站的换乘条件、行车组织等多个因素;同台换乘易实现跨线运营,因线路通过能力和可节省的换乘时间都有限,高峰期实施跨线运营优势并不明显;与单线独立运营开行方案相比,实施跨线运营可减少企业运营成本和乘客出行成本,且随着跨线客流强度的增加,成本节约效益越明显.     

基于车辆响应的桥梁间接测量与监测研究综述

中小跨径桥梁量大面广且维护投入相对较少,如何实现快速、经济且准确的状态评估与损伤诊断是交通基础设施管理中亟待解决的关键问题.2004年,Yang等首创了基于车辆响应的桥梁间接测量法(也称"车辆扫描法"),因具有高机动性、快速、可连续测试等显著优点,在国内外备受广泛关注与推崇.为了推动桥梁驱车间接测量法的技术落地并探索其...