高速公路改扩建工程路基拼接施工技术的应用分析

为了保证高速公路改扩建工程的品质,延长公路改扩建后的使用寿命,基于高速公路改扩建工程路基拼接施工的价值,论述高速公路改扩建工程路基拼接施工技术的应用,研究得出前期准备工作、科学选择路基填料、旧边沟的处理、路基边坡处理、科学控制沉降、完善排水系统等施工方法,旨在为实际工作提供一定帮助。     

高速公路改扩建工程路基施工质量控制分析

文章结合广西沿海高速公路改扩建一期工程№1合同段路基改扩建施工实例,对高速公路改扩建工程特点、路基工程扩宽施工要点等内容进行阐述,并介绍了高速公路改扩建工程路基施工质量控制的相关经验。     

公路路基防护施工技术分析

文章结合泉州至南宁高速公路柳州至南宁段改扩建工程实例,分析了公路路基边坡防护发展历程,探讨了公路路基防护施工技术方法类型,提出了路基边坡防护施工的新理念。     

高速公路改扩建工程路面施工阶段交通组织研究

为提高我国高速公路改扩建工程路面施工阶段交通组织的有效性,对高速公路改扩建工程特点进行阐述,基于高速公路改扩建工程开展需求对其路面施工阶段交通组织原则进行总结,之后梳理施工期间的交通组织要点、提出相关措施,希望能为相关领域进行更深入的研究提供参考,引发更多关于高速公路改扩建工程路面施工阶段交通组织方案制订的探讨。     

论高速公路改扩建工程的精细化管理问题

高速公路改扩建施工须采用精细化管理的施工手段,有效控制工程的工期、质量和安全。主要阐述了如何在高速公路改扩建工程前期管理、施工管理,对加强高速公路改扩建工程的精细化管理有所借鉴。     

公路改扩建工程路基路面施工关键技术

随着交通通行量的日益增多,早期建设的公路项目难以完全满足当前交通通行的需要,为提高公路交通通行效率,需进行改扩建施工。基于此,主要对高速公路改扩建工程中的关键技术进行阐释,并结合实际工程案例,对公路改扩建工程路基路面施工关键技术应用进行分析。在此基础上,提出一些施工质量控制措施,以期实现公路运输能力的全面提升,促进交通通行效率的提高,为经济社会发展提供有力支撑。     

髙速公路改扩建工程施工交通组织安全评价及关键技术措施

受诸多因素制约,国内高速公路改扩建工程通常施工时不允许中断交通,如何做好施工交通组织,是高速公路改扩建工程成败的关键。结合福泉厦漳高速公路改扩建工程,重点研究高速公路改扩建期间交通组织的安全评价及对策,并提出实现四车道保通的关键技术措施。     

高速公路改扩建若干关键问题思考

近年来我国经济高速发展,高速公路的运输压力相应增大,高速公路的改扩建工程成为了未来公路建设的一个重要组成部分。高速公路改扩建是一个复杂的系统工程,需要考虑多方面的问题,本文对其中的改扩建工程方案选择原则、新旧路基差异沉降控制、改扩建工程交通组织原则、环境保护与修复等问题进行了思考,以期能够对未来高速公路改扩建工程提供可以借鉴的经验。     

浅谈高速公路改扩建工程交通组织方案

文章结合广西沿海高速公路改扩建一期工程实例,阐述了高速公路改扩建工程施工阶段交通组织的总体方案,并介绍了在路基、路面、桥梁施工阶段的交通组织具体措施,为同类型高速公路改扩建施工提供参考。     

山区高速公路扩建工程总体设计策略分析

根据山区高速公路改扩建的工程特点,依托厦蓉高速公路改扩建工程实例,从总体设计角度出发,总结了山区高速公路改扩建路线设计协同互通、构造物、景观、施工交通组织等方面的设计策略,为类似山区高速公路改扩建工程设计技术提供参考。     

Survey of R&D in PRT systems

A survey of research and development in advanced transit has been made by Chalmers University of Technology in Gothenburg in cooperation with Trans21 in Boston. Summary findings are reported for fourteen academic research programs and ten development programs for PRT. An earlier version of this paper was presented at the International Conference of PRT and other Emerging Systems held in Minneapolis in 1996.     

Optimization of bus stop locations for improving transit accessibility

A mathematical model is developed in this paper to improve the accessibility of a bus service. To formulate the optimization model, a segment of a bus route is given, on which a number of demand entry points are distributed realistically. The objective total cost function (i.e. the sum of supplier and user costs) is minimized by optimizing the number and locations of stops, subject to non‐additive users' value of time. A numerical example is designed to demonstrate the effectiveness of the method thus developed to optimize the bus stop location problem. The sensitivity of the total cost to various parameters (e.g. value of users' time, access speed, and demand density) and the effect of the parameters on the optimal stop locations are analyzed and discussed.     

Productive efficiency and ownership of urban bus services

The established ownership mix of urban bus operations in Australia provides a unique opportunity to investigate the productivity differences between public and private bus service supply. Using duality theory in economics which links economic indices of factor productivity to the cost structure of a firm, we develop empirical measures of total and partial productivity of inputs, and adjust the differences for the effects of ownership status and operating environment. The evidence supports the notion that private supply of public passenger transport in general has performed more efficiently in the past than public supply, although the differences in productivity need not continue in the future.     

Determinants of modal choice in freight transport

In the next few years, exciting developments in the field of freight transport are likely to occur. The Channel Tunnel will be perceived as giving railways much greater distance of operation, compared to the current train ferry to/from Great Britain. The further development of swap-body technology will allow easier modal transfer and the creation, in 1992, of a single market in Europe will transform the pattern of trade. All of these are likely to have significant impacts on modal choice, and hence modal split, in freight transport. Reappraisal by many firms of the modes of transport used is likely but will it result in a net transfer of freight from road to rail and, if so, to what extent? To answer such questions, an accurate and reliable method of predicting modal split is required. Research in the past has concentrated on the development of modal split models based on generalised costs. These fail to explain adequately the prevalence of road freight in the UK. From surveys of freight managers within industry, it is clear that models to date rely too heavily on the economic cost factor and too little on behavioural factors (Jeffs 1985). This paper derives from a recent study of freight transport modal choice from the standpoint of the transport decision-maker within the firm. It attempts to shed light on the actual parameters which should be incorporated into a modal split model. Many variables appear to exert an influence on modal choice decision-making process. However, it is possible to categorise them into six main groups, namely: customer-requirements; product-characteristics; company structure/organisation; government interventions; available transport facilities; and perceptions of the decision-maker him/herself. It is the interactions and inter-relationships between these which ultimately determine freight modal split. This study has shown that the relationship between the outcome of the transport decision process and the values of particular determinants of modal split is not straight-forward, due to the complexity and variety of interactions involved. Perhaps one of the main reasons for researchers' failure hitherto to develop a successful modal-split model has been the preoccupation with techniques that rely on the development of common metric (e.g. generalised cost), which has led to the exclusion of some important explanatory variables along quite different dimensions. Another important issue concerns the appropriate level of aggregation. In order not to reduce the explanatory power of the key variables, it is important to work at a disaggregate level, although this does make substantial demands on data. The use of factor analysis enables both the aggregation of information without loss of behavioural reality and the specification of variables in terms of a common metric. In conclusion, freight transport has usually been examined within too narrow a framework. It must be placed firmly within the context of the total industrial process. The demand for freight transport is directly influenced by the level, composition and geographical distribution of production and consumption activities. Freight flows are complex and so it is highly unlikely that a universal mode-choice model can ever be developed. Future research should, therefore, be directed towards developing partial models in response to specific needs of those involved in decision-taking in the freight sector.     

管道风险分析指数评分法中分值调整初探

管道风险分析指数评分法中重要步骤之一就是确定影响管道事故因素的权重,各个管道风险因素在整个管道事故中所占的权重是不相同的。针对目前管道风险分析指数评分法基本假设之一（各因素的分值范围都是0～100分）,为了更加客观、准确、合理地反映各个风险因素对于管道事故的影响程度,提出并论述了依据层次分析法的数学逻辑性进行综合计算得出管道风险因素的权重,然后对评分法中各个因素的最高分值,根据其权重不同进行相应调整,从而增强评价者对风险因素的认识和评判能力,提高管道风险评价结果的准确性。     

天然气站往复式压缩机活塞失效分析

针对天然气站往复式压缩机活塞的断裂事故,运用失效分析方法,开展了活塞断口扫描电镜分析、能谱和金相分析。根据断口形貌的电镜和金相观察结果,结合理论知识,分析确定了该活塞发生断裂事故的主要原因,即在特定工况下该活塞的材料缺陷是造成断裂的主要因素。     

中国城市道路规划方位性问题研究

文章结合中国的传统建筑文化理念和现代科学原理,从历史文化、能源节约、环境保护、房地产定价、交通安全等多方面分析研究了城市道路在规划和设计时所应遵从的定向规则。     

A century of evolution of the accessibility concept

The concept of accessibility has acquired numerous meanings along multiple dimensions during the century of its evolution. This essay argues for the salience of two dimensions: application-based and definition-based. In its application, accessibility has incorporated positive and normative dimensions which have varied in prominence over time. In its definition, accessibility has varied between a mode of evaluation incorporating measured mobility and proximity, on the one hand, and a predefined market basket of urbanist improvements to transportation and land use systems, on the other. Advocates of the accessibility shift should emphasize both the measured approach to accessibility and accessibility’s normative side.