南京地铁换乘站地下空间开发与利用

介绍南京地铁新街口换乘站的规划、设计和建设概况.以取得的经济、社会综合效益为实例,说明在城市繁华的中心地区,结合地铁建设进行地下空间开发是必要的,也是可行的.     

Storage space allocation in container terminals

Container terminals are essential intermodal interfaces in the global transportation network. Efficient container handling at terminals is important in reducing transportation costs and keeping shipping schedules. In this paper, we study the storage space allocation problem in the storage yards of terminals. This problem is related to all the resources in terminal operations, including quay cranes, yard cranes, storage space, and internal trucks. We solve the problem using a rolling-horizon approach. For each planning horizon, the problem is decomposed into two levels and each level is formulated as a mathematical programming model. At the first level, the total number of containers to be placed in each storage block in each time period of the planning horizon is set to balance two types of workloads among blocks. The second level determines the number of containers associated with each vessel that constitutes the total number of containers in each block in each period, in order to minimize the total distance to transport the containers between their storage blocks and the vessel berthing locations. Numerical runs show that with short computation time the method significantly reduces the workload imbalance in the yard, avoiding possible bottlenecks in terminal operations.     

双速搅拌工艺

根据传统二次搅拌理论,提出了混凝土双速搅拌工艺,介绍了双速搅拌工艺的原理及优点,并指出了该工艺的实现方案.该工艺的应用可降低生产成本,提高混凝土的强度和生产率.     

超大跨度斜拉桥施工过程力学行为

斜拉桥结构效应在施工过程中具有典型的时空变化特性，但目前对效应的时程特性及时空包络关注较少。建立精细的几何非线性分析模型，分析主跨1088m的苏通大桥施工过程力学行为，包括施工阶段效应增量、效应时程、效应包络及恒载效应。研究结果有助于结构设计和施工控制。     

Dynamic stride length adaptation according to utility and personal space

Pedestrians adjust both speed and stride length when they navigate difficult situations such as tight corners or dense crowds. They try to avoid collisions and to preserve their personal space. State-of-the-art pedestrian motion models automatically reduce speed in dense crowds simply because there is no space where the pedestrians could go. The stride length and its correct adaptation, however, are rarely considered. This leads to artefacts that impact macroscopic observation parameters such as densities in front of bottlenecks and, through this, flow. Hence modelling stride adaptation is important to increase the predictive power of pedestrian models. To achieve this we reformulate the problem as an optimisation problem on a disk around the pedestrian. Each pedestrian seeks the position that is most attractive in a sense of balanced goals between the search for targets, the need for individual space and the need to keep a distance from obstacles. The need for space is modelled according to findings from psychology defining zones around a person that, when invaded, cause unease. The result is a fully automatic adjustment that allows calibration through meaningful social parameters and that gives visually natural results with an excellent fit to measured experimental data.     

Coloured Petri net-based traffic collision avoidance system encounter model for the analysis of potential induced collisions

The Traffic Alert and Collision Avoidance System (TCAS) is a world-wide accepted last-resort means of reducing the probability and frequency of mid-air collisions between aircraft. Unfortunately, it is widely known that in congested airspace, the use of the TCAS may actually lead to induced collisions. Therefore, further research regarding TCAS logic is required. In this paper, an encounter model is formalised to identify all of the potential collision scenarios that can be induced by a resolution advisory that was generated previously by the TCAS without considering the downstream consequences in the surrounding traffic. The existing encounter models focus on checking and validating the potential collisions between trajectories of a specific scenario. In contrast, the innovative approach described in this paper concentrates on quantitative analysis of the different induced collision scenarios that could be reached for a given initial trajectory and a rough specification of the surrounding traffic. This approach provides valuable information at the operational level. Furthermore, the proposed encounter model can be used as a test-bed to evaluate future TCAS logic changes to mitigate potential induced collisions in hot spot volumes. In addition, the encounter model is described by means of the coloured Petri net (CPN) formalism. The resulting state space provides a deep understanding of the cause-and-effect relationship that each TCAS action proposed to avoid an actual collision with a potential new collision in the surrounding traffic. Quantitative simulation results are conducted to validate the proposed encounter model, and the resulting collision scenarios are summarised as valuable information for future Air Traffic Management (ATM) systems.     

桨-舵间距对其组合系统水动力性能的影响

本文通过CFD方法对敞水桨、桨-舵组合以及优化间距的桨-舵组合装置开展了数值仿真研究，分析了桨-舵间距对其组合系统的水动力性能影响。螺旋桨敞水工况的计算值与物理模型试验值吻合良好，验证了数值计算方法的可行性。通过对比桨-舵间距大于推荐值的三个工况，发现在较低进阶系数下系统的节能效率有稍许增加，然而随着间距的增大，节能效率呈现降低的趋势；在高进阶系数下，随间距增大节能效率逐步降低。适当减小桨-舵间距，在较低和中等进阶系数下，随间距减小节能效率呈现逐步升高的趋势，在间距减少10mm时，组合体的节能效率最大可增加1.937%；不过在高进阶系数下，随间距减小节能效率却有下降趋势。     

25t轴重荷载作用下隧底脱空区域受力特性分析

为了研究在役铁路隧道在通车之后隧底脱空病害的问题,采用有限元理论,建立隧道脱空区域在围岩压力与25 t轴重列车动载作用下的数值计算模型,主要研究80 cm与40 cm脱空宽度分别距隧道中心线0,80 cm与160 cm时脱空区域的受力特性。结果表明:在围岩压力下,脱空区域中线上壁和外侧顶角混凝土中产生拉应力及内侧顶角中产生压应力,其中压应力对脱空的宽度更为敏感;同时施加列车动载作用时,脱空区域上壁出现了竖向动应力与横向拉应力,得到了脱空区域力学指标的最大响应值及其出现的具体位置,宽度的增加对脱空区上壁横向拉应力更为显著,上壁横向拉应力增幅超过200%,竖向动应力增幅达50%。因此,隧底脱空区周围应力分布复杂,拉应力与压应力在脱空区域同时存在,应力突变严重,对脱空现象应及时组织处理。     

铁路沿线城市空间物业开发研究——以宝鸡市南客站核心区站前广场工程为例

为了提升铁路沿线城市空间物业开发的设计手法,结合宝鸡市南客站核心区站前广场工程的设计实践,从系统性设计观、工程性质解析、消防设计思路、空间建构方法、无缝接驳、技术要素等方面进行研究分析,展示将铁路与城市系统进行一体化设计、利用自然资源解决消防和投资问题、平层空间中对多种交通体系的有机组织、不同坐标和高程系统背景下分区域构建柱网、各板块交接处的问题解决等技术成果,总结出同类型建筑的设计思路,力求为该领域的建筑设计发展提供有益的借鉴。     

考虑空车调配协调的货物列车开行方案优化研究

为实现空车调配与货物列车开行方案协调优化，结合基本运行图架构与车流径路，构建货运时空服务拓展网络。考虑配空与装卸取送、集编发等环节的时间接续要求，节点与区段不对流空车要求，以重车流全程运送与空车配送等广义总费用最少为目标，建立整数规划弧路模型。针对既有算法设计局限性，结合重车或空车配空的时间接续要求，提出将不同的 k 短路重车流方案与空车配空方案相关联的改进可行解构造方法，设计混合差分进化求解算法。实例研究表明，考虑空车调配进行重车、空车流组织协调优化，能够减少空车走行费用，及时满足装车需求，有效保证作业车流配合中转车流集结编组及时挂线，提高方案可实施性。