机场水泥混凝土道面使用寿命的改进灰色预测模型

为了准确预测机场水泥混凝土道面使用寿命,根据道面的使用性能特点,确定道面破损度为道面使用寿命的控制指标.采用灰色系统理论建立了道面使用寿命灰色预测模型,利用计算原点残差的方法检验模型的精度,并采用数据序列中最近时间点的实测值为求解的初始条件改进模型求解过程.研究结果表明:机场水泥混凝土道面破损度与道面使用时间呈指数型递增关系,道面剩余使用寿命随使用时间呈指数型衰减;道面破损度预测值与实测值的误差不超过5%,因此,该模型有效,可用于定期检测的道面.     

Robust Optimization of Hub-and-Spoke Airline Network Design Based on Multi-Objective Genetic Algorithm

In the process of designing hub network, the selection of hub airports is influenced by the change of the demand and cost. Under the condition of changing in demand, this may lead to large minimum cost deviation between the designed optimal network and real optimal network, respectively. To reduce the risk caused by the uncertainty in network optimization and get the optimal robust solution of hub network under the multi-possible conditions of demand and cost, a method based on multi-objective optimization genetic algorithm is proposed in this paper. The convergence of the algorithm has been proved, and the experimental results demonstrate the availability of the algorithm. First, multiple objective functions needing to be optimized simultaneously are formulated from different conditions of needs and cost, then a genetic algorithm is used to provide all possible routes of the network hub structure, and robust optimal network solution for multi-objective optimization is searched. The convergence of the search algorithms is proved to be effective by the numerical results.     

大型会展场馆与城市机场的时空距离研究

本文通过对国内具有5万平方米及以上室内展览场地的大型会展场馆与城市机场之间的在线交通数据分析和理论假设验证,发现:(1)两地之间的直线距离平均为22 km;(2)两地之间乘坐专用车辆的平均时间为36 min,乘坐大型公共交通工具的平均时间为90 min;(3)GDP越高或常住人口越大的城市,或职工月工资水平越高的城市,...     

Crosswind‐based optimization of multiple runway orientations

The runway orientation must satisfy the operational requirements of aircraft for landing and takeoff. Actually, the runway orientation is the result of compromises between the airport usability (wind coverage) and additional factors, such as available land, existing obstructions, topographic difficulties, flight path interference among runways and airports, noise pollution, and other environmental impacts. Therefore, the solution of a combination of acceptable runway orientations, which avoids excessive crosswinds at least 95% of the time, as well as the optimal orientation solution, is essential to conduct those compromises in the runway orientation analysis. The objective of this paper is to develop a computer model, named the optimization of multiple runway orientations model, which is capable of simultaneously providing a combination of acceptable runway orientations, changing the allowable crosswind limit flexibly, and determining the optimal orientations of multiple runway configurations. Instead of visual estimation or geometric computation, this paper presents an analytical method for wind coverage analysis. The model is mainly running in spreadsheet and Visual Basic for Applications (VBA). The numerical example and comparison show that the optimization of multiple runway orientations model is competitively accurate and convenient in comparison with previous ones. This paper presents an up‐to‐date model for the optimization of multiple runway orientations. By combining it with the geographic information system obstructions model, it can become an essential element of a future model for airport development cost minimization that combines airfield land use, earthwork volume, and cost estimation modules. Copyright © 2013 John Wiley & Sons, Ltd.     

飞机除冰液对停机坪水泥混凝土的影响

通过除冰液成分分析、混凝土试件除冰液浸泡实验、物相分析和冻融理论分析，探讨了剥落损坏发生的原因和机理。研究发现除冰液和水泥混凝土之间并不会发生化学反应；除冰液的渗入会增加混凝土内的水压力、渗透压、蒸气压差异和温度梯度。结果表明，除冰液参与下的剥落属于物理损坏，主要由冻融循环引起；除冰液的存在和入渗加剧了混凝土表面层的冻融剥落发生。建议从减少除冰液的用量、使用范围、与混凝土的接触时间，以及混凝土的抗冻等方面进行剥落防治。     

机场道面混凝土冻融破坏评价指标

为了研究中国北方寒冷地区机场道面混凝土冻融破坏的评价指标,制作了3种不同抗冻性能的混凝土试件,采用快速冻融试验机对混凝土试件进行了冻融破坏试验,并用动弹仪DT-10W测试了试件的动弹性模量,分析了不同冻融循环次数作用下试件相对动弹性模量、压折强度、质量损失及表面剥落的变化规律,给出了机场道面混凝土冻融破坏的临界值。试验结果表明:随着冻融循环次数的增加,试件的压折强度均有不同程度的下降,其中抗折强度的损失较大,且试件表面剥落面积及深度增大,质量损失对试件表面平整度的影响严重。根据试件在冻融过程中相对动弹性模量与抗折强度损失、表面剥落与质量损失的规律,建议以300次快速冻融循环后混凝土试件相对动弹性模量不小于75%(抗折强度损失率不大于46%)和质量损失率小于1.0%(中等剥落)作为机场道面混凝土冻融破坏的评价指标。     

2020年中国轨道交通机场线统计及空轨协同运营分析

轨道交通在联通机场枢纽与城市中心区之间发挥了重要作用,包括干线铁路、城际铁路、市域(郊)铁路、城市轨道交通等多种形式,统称为轨道交通机场线。截至2020年末,中国已有35个城市的38个机场连接轨道交通线路;另有在建线路23条,涉及19个机场;尚在规划线路35条,涉及29个机场。统计已经运营和正在建设、尚在规划的轨道交通机场线基本情况,结合国内外机场线的成熟经验总结了机场与轨道交通(简称“空轨”)协同运营的情况,并提出轨道交通机场线与机场的协同运营的建议,包括运营时间、票制票价、场站衔接、客流应急等方面。     

北京轨道交通新机场线轨道系统设计综述

北京轨道交通新机场线一期工程设计速度为160 km/h,突破了既有城市轨道交通规范规定的速度范畴,既有的轨道系统结构形式已无法满足本工程高速行车的需求。同时,本工程还存在通过地段人工地物复杂多样、人员疏散性要求高、建设工期紧张等问题,给轨道系统设计带来了诸多挑战。在没有设计先例、没有规范遵循的情况下,采用"城际"标准与"地铁"标准相结合的设计思路与方法,设计了适用于不同地段的轨道系统结构形式,提出了基于轨面平顺性控制的成套技术方案。北京新机场线的成功开通运营表明,采用"城际+地铁"相结合的方法可解决更高速度下城市轨道交通轨道系统结构的高稳定性、高平顺性等设计问题。该设计思路与方法可为今后城市轨道交通类似线路提供设计范例,同时也为市域快线及市郊铁路轨道系统设计提供了新思路。     

Simulation-based assessment methodology to improve ground service operations at a hub airport

ABSTRACT

Airport terminals are dynamic environments and security/passport services generally constitute costly bottlenecks in terminals. Increases in the number of airline passengers compels airport terminals to provide more efficient services to its customers under space and resource limitations. This study examines the level of service of passenger processes at Istanbul Atatürk Airport by constructing a comprehensive simulation model. It focuses mainly on passport control services and passenger transfer security services because of the airport's hub status and the strategy of Turkish Airlines. The increasing number of transfer passengers may cause disruptions in departure flight schedules due to slow passenger processes. After validating the model, we investigate the consequences of three main alternative solutions, including 17 sub-scenarios, to capture target quality levels. Finally, we provide the results for each scenario to investigate the optimum allocation of resources to terminal operations.     

客货共运下机场线列车运行计划与货运分配方案协同优化

机场线具备利用富余能力开展城市货运服务的潜力。针对机场线客货共运问题，基于客货共载和货运专列两种货物运输形式，以考虑仓储、装卸及列车运行成本的货运净收益最大为目标，构建列车运行计划与货运分配方案协同优化模型，综合决策货运专列的编组停站方案、时刻表和货单分配。为快速求解模型，设计一维搜索算法对货运专列开行数量进行寻优。通过允许货运专列编组为0，保证搜索过程目标值单调递增，并利用Gurobi求解给定货运专列开行数量下的子问题。基于某市机场线案例结果表明，在不影响客运服务前提下，本文方法选择性满足货运需求，增加运营收益。相较于站站停模式，优化列车停站方案可增加5.2%的净收益；相较于固定编组模式，灵活编组在不同货运量和时效要求下可增加5%~35%的净收益，且时效要求较高时，灵活编组优势较为明显。