变道约束下近邻交织区交通均衡组织方法

针对相邻较近的交织区车辆持续交织运行特点,以提高交织区通行效率及交通安全为目标,提出一种基于变道约束下近邻交织区交通均衡组织方法,旨在计算不同时段交通量所对应近邻各交织区的最佳提前变道诱导距离,以减少近邻交织区车辆相互干扰,降低平均交通延误,提高道路通行效率.对重庆市海峡路两段近邻交织区的日均交通量(4 092 pcu/h),早高峰时段交通量(5 340 pcu/h),晚高峰时段交通量(4 596 pcu/h),以及年均交通量(3 276 pcu/h)进行仿真建模分析.实验选取近邻交织区内累计平均延误作为近邻交织区的评价指标,利用仿真软件(Vissim 4.3)持续仿真 40次.结果表明,最佳提前变道约束距离为交织区长度的 60%,其相应的平均交通延误分别降低了57%、73%、63%和72%.     

北京地铁13号线故障情况下运营方案研究

北京地铁13号线是北京城市轨道交通的第一务地面线路。分析影响列车运行的客观因素和线路特点,介绍针对不同区段线路阻隔而制定的行车组织方案,以在保证安全的前提下最大限度地满足乘客需求．     

基于“互联网+”的海洋钻井平台系统结构研究

互联网技术作为第三代工业革命的核心技术,为海洋钻井平台系统提供了新的发展方向。本文提出的基于“互联网+”的海洋钻井平台系统结构,结合了互联网技术的优势,优化了平台信息流和能量流;在原有电力控制网络的基础上,增加了“互联网+”远程故障诊断网络,以提高平台故障的排除速度;增加了“互联网+”海洋气象信息网络和海洋地质勘探网络,以提高平台的环境预测能力和地质勘探实时性;设计了基于互联网的能量管理系统可实现框架,将互联网和海洋钻井平台融合起来;还展望了基于“互联网+”海洋钻井平台的发展前景。     

Study on the methods of precision controlling for the manufacture of hull curvature sections

1 Introduction1 The precision controlling technology is a key step for model ship construction. The core of precision controlling technology lies in reducing the scene repetition to a minimum during the course of construction and revising the working quan…     

绞吸式挖泥船剖面工作轨迹计算

通过对绞吸式挖泥船进行几何建模,推导出绞吸式挖泥船疏浚宽度、疏浚深度工作轨迹公式,为开发自主知识产权的智能化挖泥操作设备建立数学基础。     

Evaluating the effects of automated vehicle technology on the capacity of freeway weaving sections

Weaving sections, where a merge and a diverge are in close proximity, are considered as crucial bottlenecks in the highway network. Lane changes happen frequently in such sections, leading to a reduced capacity and the traffic phenomenon known as capacity drop. This paper studies how the emerging automated vehicle technology can improve the operations and increase the capacity of weaving sections. We propose an efficient yet effective multiclass hybrid model that considers two aspects of this technology in scenarios with various penetration rates: (i) the potential to control the desired lane change decisions of automated vehicles, which is represented in a macroscopic manner as the distribution of lane change positions, and (ii) the lower reaction time associated with automated vehicles that can reduce headways and the required gaps for lane changing maneuvers. The proposed model is successfully calibrated and validated with empirical observations from conventional vehicles at a weaving section near the city of Basel, Switzerland. It is able to replicate traffic dynamics in weaving sections including the capacity drop. This model is then applied in a simulation-based optimization framework that searches for the optimal distribution of the desired lane change positions to maximize the capacity of weaving sections. Simulation results show that by optimizing the distribution of the desired lane change positions, the capacity of the studied weaving section can increase up to 15%. The results also indicate that if the reaction time is considered as well, there is an additional combined effect that can further increase the capacity. Overall, the results show the great potential of the automated vehicle technology for increasing the capacity of weaving sections.     

高速公路桥隧连接段安全评价指标体系研究

通过分析相邻互通式立交之间连接段、互通式立交与隧道之间连接段以及前后两相邻隧道之间连接段的结构特点,提出基于土建结构的高速公路桥隧连接段评价指标体系,包括变速车道长度、渐变段长度、两渐变段之间的长度、隧道口与互通式立交渐变段之间的长度以及前后相邻两隧道间距等评价指标。计算得出各指标对应不同运行速度、不同车道数以及不同交通量要求的安全值。     

拱塔斜拉桥桥塔钢-混结合段空间受力分析

斜拉桥桥塔钢-混结合段结构复杂,构件众多,使得其受力状态极为复杂.以某拱塔斜拉桥的桥塔钢-混结合段为基础,利用Midas/Civil建立空间杆系模型,进行整体静力分析,确定桥塔钢-混结合段部位3种最不利荷载工况,得出其荷载和位移的边界条件.再利用大型空间有限元软件ANSYS,建立桥塔钢-混结合段三维实体模型,并进行受力分析,明确钢-混结合段处钢板和混凝土的受力性能.计算结果表明:钢-混结合段的变形较小,钢板和混凝土的应力水平较小,结构的安全储备良好.     

铁路列车沿线车外气象参数模型的建立

借助时间序列分析的思想采用RBF神经网络针对特定铁路客车沿线建立了全年的逐时气象参数(温度与太阳辐射)模型。为铁路客车运行过程性能研究和能耗仿真研究提供了基础。     

北京地区水泥混凝土路面温度场研究及气象要素分析

水泥混凝土路面承受着各种环境因素的综合作用,这种作用的结果直接体现为路面温度场的复杂分布.通过实测1年的气象要素数据及水泥混凝土路面板温度场数据,分析了北京地区气温和太阳辐射的变化规律,最终得到30 cm水泥混凝土板的温度场和温度梯度规律.