提高土压式盾构在砂砾石地层中掘进刀具耐用性的对策

该文结合北京地铁10号线11标总长度约2.8km的区间隧道工程的土质条件,从刀盘形式、刀具布置、加泥材料及施工措施等方面,阐述了在砂砾地层中提高土压平衡盾构掘进机的刀盘切削刀具耐用性的一些有效对策,为盾构选型和类似工程施工提供参考。     

基于光纤数字通信的直流双边联跳保护方案

介绍北京地铁亦庄线在国内轨道交通工程中首次应用的基于光纤数字通信的直流双边联跳保护方案.阐述方案的回路构成、联跳动作原理,分析方案设计过程中需要重点考虑的环节,并提出具体要求.与传统电缆传输信号的直流双边联跳方案进行综合经济技术比较,表明新方案具有良好的抗干扰性能、数据传输可靠性高,可以适用于任何工程环境.     

北京南站客流流线的分析与优化组织

针对北京南站各层之间换乘的复杂性,分析北京南站现行的客流流线组织方式,并对客流流线做分类。通过对换乘流线以及北京南站在客流组织流线设计中存在的一些问题分析,提出客流组织流线的优化调整方案。     

中国美术馆站外挂厅结构盖挖逆作法设计要点探讨

为探讨盖挖逆作法结构设计的要点和难点,以北京地铁8号线中国美术馆站西北外挂厅设计为例,介绍了盖挖逆作法结构的适用条件。通过对盖挖顺作和逆作2种方案进行比选,确定了逆作的设计方案;阐述了设计思路和要点、结构计算以及防水等关键节点的处理,并对钢管柱柱下基础形式、顶板与边桩冠梁的连接方式进行了比选、论证;最终采用暗挖小导洞内施作底纵梁作为钢管柱柱下条形基础,顶板与边桩冠梁采用固接方式连接,解决了施工用地紧张的难题,保证了周边建筑的安全。     

北京市交通结构合理发展模式及策略研究

在交通需求总量保持高速增长,而道路资源能力扩充有限的背景下,交通结构是否合理直接影响交通资源的配置方式以及城市交通系统的运行效率。首先总结北京市交通结构发展的历史阶段及特征。然后,系统梳理国际大城市三种典型的交通发展模式及策略。在此基础上,针对北京市交通结构调整面临的主要问题与挑战,相应提出交通结构合理化发展的策略与建议：提升公共交通吸引力和承载力、降低小汽车使用强度、引导市民绿色出行和理性消费。     

The impacts of mass transit on land development in China: The case of Beijing

Land development impacts of mass transit have long been studied in the developed economies. Yet relatively little is known by the outside world about the Chinese experience due to China's rather short history in the development of modern mass transit and land/property market. This paper attempts to fill the gap by presenting evidence from China, with a detailed case study of Beijing. Selecting three newly built suburban transit lines in Beijing, the study examined land development context and estimated hedonic housing price models to measure the proximity premiums associated with these three lines. The empirical evidence in Beijing, one of the first tier mass transit cities in China, shows that investments in mass transit can have significant and positive impacts on land development. Properties with transit proximity enjoy sizable price or value premiums. The study also confirms the international experience: transit impacts on land development are unlikely to occur automatically; they rely greatly on supportive regional and site conditions. Integrated planning and design for mass transit and land development are critical to expand and maximize the return of transit investments.     

Commuting trip satisfaction in Beijing: Exploring the influence of multimodal behavior and modal flexibility

In the past decade, many studies have explored the relationship between travelers’ travel mode and their trip satisfaction. Various characteristics of the chosen travel modes have been found to influence trip experiences; however, apart from the chosen modes, travelers’ variability in mode use and their ability to vary have not been investigated in the trip satisfaction literature. This current paper presents an analysis of commuting trip satisfaction in Beijing with a particular focus on the influence of commuters’ multimodal behavior on multiple workdays and their modal flexibility for each commuting trip. Consistent with previous studies, we find that commuting trips by active modes are the most satisfying, followed by trips by car and public transport. In Beijing, public transport dominates. Urban residents increasingly acquire automobiles, but a strict vehicle policy has been implemented to restrict the use of private cars on workdays. In this comparatively constrained context for transport mode choice, we find a significant portion of commuters showing multimodal behavior. We also find that multimodal commuters tend to feel less satisfied with trips by alternative modes compared with monomodal commuters, which is probably related to their undesirable deviation from habitual transport modes. Furthermore, the relationship between modal flexibility and trip satisfaction is not linear, but U-shaped. Commuters with high flexibility are generally most satisfied because there is a higher possibility for them to choose their mode of transport out of preference. Very inflexible commuters can also reach a relatively high satisfaction level, however, which is probably caused by their lower expectations beforehand and the fact that they did not have an alternative to regret in trip satisfaction assessments.     

Decomposition analysis of energy-related carbon emissions from the transportation sector in Beijing

In the process of rapid development and urbanization in Beijing, identifying the potential factors of carbon emissions in the transportation sector is an important prerequisite to controlling carbon emissions. Based on the expanded Kaya identity, we built a multivariate generalized Fisher index (GFI) decomposition model to measure the influence of the energy structure, energy intensity, output value of per unit traffic turnover, transportation intensity, economic growth and population size on carbon emissions from 1995 to 2012 in the transportation sector of Beijing. Compared to most methods used in previous studies, the GFI model possesses the advantage of eliminating decomposition residuals, which enables it to display better decomposition characteristics (Ang et al., 2004). The results show: (i) The primary positive drivers of carbon emissions in the transportation sector include the economic growth, energy intensity and population size. The cumulative contribution of economic growth to transportation carbon emissions reaches 334.5%. (ii) The negative drivers are the transportation intensity and energy structure, while the transportation intensity is the main factor that restrains transportation carbon emissions. The energy structure displays a certain inhibition effect, but its inhibition is not obvious. (iii) The contribution rate of the output value of per unit traffic turnover on transportation carbon emissions appears as a flat “M”. To suppress the growth of carbon emissions in transportation further, the government of Beijing should take the measures of promoting the development of new energy vehicles, limiting private vehicles’ increase and promoting public transportation, evacuating non-core functions of Beijing and continuingly controlling population size.     

北京地铁车站导向标识系统调查分析

阐明地铁车站导向标识系统设计的重要性,设置的内容、形式和位置应规范统一,体现人性化理念。阐述地铁车站导向标识系统设计的原则,通过实地调研。分析北京地铁换乘站导向标识系统的设计现状问题;结合国外地铁标识系统的设置原则,对我国地铁车站标识系统设计提出参考建议。     

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在轨道交通系统中,列车的运行控制系统是确保列车运行安全和提高列车运行效率的核心子系统。列车运行机理的分析,列车追踪模型和算法的建立,是开发列车运行控制系统的基础。本文根据地铁列车追踪运行的特点,建立了固定自动闭塞系统下的元胞自动机模型,并对北京地铁2号线进行了模拟仿真。通过时空图和速度—时间—位移图,我们研究和探讨了地铁列车追踪运行的一些主要特性,分析了速度、时间、位置之间的相互变化。模拟结果再现了地铁列车运行时列车流的动态特性。通过对比分析模拟结果和实际运行结果发现,所提出的模型是一种有效的模型,可以很好地用来描述地铁中列车运行的特点。