支架法在海中箱梁现浇施工中的应用

针对海中箱梁现浇施工中的工程量大、工期紧迫、悬臂法施工不能满足工期要求和施工难度大等问题，文章结合青岛海湾大桥箱梁现浇施工实践，介绍以钢管桩支撑作为承载基础，采用贝雷梁与碗扣式支架相结合的支架，成功地解决现浇箱梁施工难题的方法。     

Role of the Railways in the Future of Air Transport

Abstract

The role of the railways in the air transport industry is usually limited to provision of access to airports. However, the development of high-speed rail networks and the congestion and environmental problems faced by the air transport industry suggest the railways could have a greater role in working with the airlines to provide an integrated transport service for medium-distance journeys (up to 800 km). Many air journeys involve two flights and a transfer at a hub airport. The alternative being investigated here would replace air journeys by a rail journey and a flight, and a transfer between them at the hub airport. Such integration could offer a positive alternative to aircraft on some routes and lead to railway journeys to airports becoming part of air transport services, and not only to provide access to them. Integration could therefore provide a better use of available air capacity rather than duplicating some high-speed rail routes and services.     

谈谈索道驱动机减速机的润滑问题

文章阐述了索道减速机润滑的重要性，介绍了加强润滑的技术措施以及对润滑油的技术要求。     

风积沙在沙漠区域填砂路基公路施工中的应用

文章通过对沙漠区域风积沙的物理力学性质和工程特性的分析,结合某省级公路工程试验段风积沙路基施工方案,介绍了风积沙路基的施工工艺与质量控制要点,并探讨了以风积沙作为路基填筑材料的技术处理方案,为沙漠地区路基施工提供参考。     

A test of the two-mode UMOT in the Netherlands

The UMOT model, presented as an alternative to conventional travel demand models, is critically examined for its feasibility to predict vehicle distance travelled and average daily traffic in The Netherlands. Using data from the National Travel Survey (OVG) 1978 a Dutch version of UMOT is developed, and an attempt is made to validate it on historical data from the period 1960 to 1980. Some comparisons are made with results of similar work using 1976 survey data in the UK by the Transport and Road Research Laboratory.     

Problems of the carless in the United Kingdom and the United States

An examination of current population statistics shows that in the U.S. more than half of the population is without immediate access to a car, and in the U.K. more than three-fifths of the population is without access to a car. This phenomenon has been accentuated by national investment in both countries in major highway programs. The term carless refers to more than just households that own no cars. It extends, in households with cars to those without licenses (old and young), the handicapped, and even the licensed drivers who have no access to the family car when it is in use elsewhere (e.g. at work). The most severely effected are those in urban areas and especially the urban poor. Transportation expenses are limited for the poor when other family expenditures (food, shelter) take a high priority. Once the work trip has been satisfied, money for other trips, for the poor, is not always available. One solution to cost-free travel is pedestrianism (walking), but this too is difficult in urban areas where the pedestrian has been overlooked in favor of the car. Solutions to problems of the carless include dial-a-ride, better public transit, and better design of urban form.     

An exploration of the importance of social influence in the decision to start bicycling in England

The purpose of this paper is to gain a better understanding, through qualitative exploration, of the ways in which social influence affects the decision to start bicycling in England. ‘Social influence’ is defined as the process by which an individual’s thoughts and actions are changed by the thoughts and action of others. Its role was investigated at three levels: the immediate family, household members and significant others (direct social influence); the extended family, friends, peers and colleagues (less direct social influence); and the wider cultural context (indirect social influence). Interviews with 61 individuals living in 12 towns and cities across England were analysed. Half of the interviewees were new regular bicyclists and the other half did not bicycle at all, or only occasionally. Social influence was found to be the dominant factor for a minority of the cases where participants started bicycling regularly. It played a role alongside other factors in other cases. It could take the form of direct influence from family, friends and peers or indirect influence from the social and cultural context. The analysis illustrates the difficulty of capturing social influence which is often hidden and emerges incidentally in the course of the interviews and interacts with other contributing factors. The role of social influence found in this research challenges the rational approach to explaining travel decision making that has traditionally dominated transport studies. The paper suggests that social processes could be harnessed to improve the efficacy of bicycling promotion programs.     

The variation in the value of travel-time savings and the dilemma of high-speed rail in China

This paper examines the variation in the value of travel-time savings (VTTS), a fundamental element determining the market demand for high-speed rail. Following a review of time allocation theories, a time allocation model for general travel behavior is proposed as a further elaboration of Evans’ (1972) activities analysis. There are relationships among activities that can be expressed using a linear inequality to show the constraints on the arrangement of activities. This model indicates that two or more activities can be simultaneously rearranged to improve time management, which may be a source of variation in VTTS. This time allocation model can explain why large-scale high-speed rail construction in China faces significant market risks and a high likelihood of economic loss. Data from a new ticket sales and booking system for railway passengers indicate that passengers prefer conventional overnight sleeper trains, rather than high-speed trains, for long-distance travel, which supports the analysis of the time allocation model.     

土工合成材料在国外路基加筋中的应用研究

文章总结回顾国外土工合成材料加筋路基力学机理、试验研究及设计方法研究现状,通过对现有路基加筋设计方法进行比较,指出现有土工合成材料加筋设计方法的不足,并就今后需进一步研究的领域提出建议。     

The influence of built environment to the trends in commuting journeys in the Netherlands

In this paper we describe commuting trends in the Netherlands in the past decade and examine the influence of urban form and travel accessibility on commuting journeys over time on the basis of data from the Dutch National Travel Survey. Exploratory analysis is performed to identify changes in commuting participation, departure time, commuting time, commuting distance and the modal split. Regression analysis and choice models are used to examine the influence of the built environment on commuting parameters over time. The results indicate that urban form has consistently influenced the parameters of commuting journey in the Netherlands in the last 10 years. However, the trend of the influence is unique for each commuting model. Some influences have become less significant in the last decade and some have become stronger.

Route structures in air transportation—the situation in the federal republic of Germany

This paper deals with route structures in air transportation in general and describes the derivation of such structures. Based on an extensive analysis of scheduled air traffic in Germany, an overview of the situation in domestic and international air travel is given. In particular, relationships were found which permit—in connection with a number of influencing factors—to derive from the present situation route structures, which are also valid for a future year.

This approach was used for the assignment of origin‐destination‐passenger flows to air network routes in a forecast of demand and services in commercial air transportation of the Federal Republic of Germany for the year 1995.     

公路隧道施工地质工作管理探讨

作者通过大量工程调研,对目前公路隧道工程地质工作的现状和存在的问题进行了深入的分析,着重探讨了如何加强对隧道地质工作的管理,并对一些关键问题和环节提出了具体管理方法和建议。     

造价工程师在项目管理中的投资控制

投资控制工作的方法是否合理,直接影响到工期和质量,投资控制工作的好坏,直接影响整个项目的的管理效果,在保障工程质量和工程进度的前提下,保证工程投资不超投资计划。     

复合式TBM在重庆地铁实践中的关键技术研究

文章通过复合式TBM在重庆轨道交通六号线工程中的应用实践,对复合式TBM的特点及其工程适应性进行了分析;对衬砌断面及其支护参数的设计、超深竖井及其支护参数的设计,以及复合式TBM穿越建筑物的施工微扰动控制设计等几大关键技术方案进行了详细阐述;明确了设计方案的合理性与先进性.     

乔庄隧道穿越软弱围岩施工力学行为分析

文章以济邵高速公路乔庄隧道为例,应用有限元程序对软弱围岩段隧道实体建模,采用二维弹塑性地层-结构模型模拟隧道施工全过程,得到了初期支护和二次衬砌等支护构件的受力和围岩位移收敛状况;同时,通过比较表明,拱顶下沉和拱腰水平收敛以及支护受力现场实测值与理论计算数据两者变化规律基本吻合。由此说明,采用现场动态监控量测与有限元仿真模拟相结合的方法可为隧道衬砌设计和安全施工提供可靠的科学依据和技术指导。     

超声导波技术在压力管道腐蚀检测的应用研究

在传统的管道腐蚀检测技术中,一般采用逐点测量管壁厚度的方法检测管道的局部腐蚀,无法实现管道的全面检测,并且无法对占压、跨越、穿越和未开挖等处的地埋管道进行腐蚀检测。目前,导波技术在国内外压力管道腐蚀检测中得到了广泛的应用,在解决了上述问题的同时,此项技术在应用过程遇到了一些技术难题,特别是管道缺陷信号的提取和辨识。文中介绍了管道导波检测的基本原理和导波应用的案例。     

Evaluating the efficiency of the Essential Air Service program in the United States

Essential Air Service (EAS) is a federally funded program in the United States that provides connecting, commercial air service between rural communities and their nearest large or medium commercial hub airport. During fiscal year 2010, $170 million dollars were spent to provide this service to 107 communities in the US. However, with significant variations in subsidies to each airport (ranging from $427,757 to $3,082,403) and marked differences in passengers served, there are serious concerns regarding the overall efficiency of the EAS program. The purpose of this paper is to use data envelopment analysis integrated in a geographic information system for evaluating service efficiencies at the community level. Policy implications and strategies to improve the EAS program are discussed.     

Discontinuities in the Lagrangian formulation of the kinematic wave model

In this article we demonstrate how network components can be modeled using the kinematic wave model in the Lagrangian formulation. This includes modeling nodes (or discontinuities) such as inflow and outflow boundaries, merges and bifurcations (e.g. ramps) and nonhomogeneous roads. Nodes are usually fixed in space. This makes their implementation in Lagrangian coordinates where the coordinates move with the vehicle more complex than in Eulerian coordinates where the coordinates are fixed in space. To this end we derive an analytical node model. The article then discusses how to implement such sink and source terms in a discretized version of the kinematic wave model in Lagrangian coordinates. In this implementation several choices have to be made. Test results show that even with the most simple choices (discretization based on full vehicle groups and discrete time steps) accurate and plausible results are obtained. We conclude that the Lagrangian formulation can successfully be applied for simulation of networks of nonhomogeneous roads.     

An analysis of the methods used to calculate the emissions of rolling stock in the UK

The aim of this paper is to analyse and compare the methods used for calculating emissions of UK rolling stock based on their type and mode of operation. The three modes under comparison were; diesel, electric and bi-mode. As well as comparing these three modes of operation, a comparison between Conventional, Freight and High Speed Rail was made. Alternate fuels were considered for diesel and bi-mode locomotives and compared based on their environmental impact. The emissions of trains were studied using three methods. Specifically, the three chosen methods were used to calculate the emissions of each train and a comparison of these methods was made. In the current UK energy climate, diesel trains emit less emissions than electric trains when factoring in mechanical and air resistances. Bi-mode trains have their place in the UK network but with electrification of the network currently in place, this mode of operation will become redundant in the near future. High Speed Rail, although time efficient, releases high emissions due to energy consumption increasing with the square of speed. Alternative fuels, such as biodiesel, should be a consideration for the future of rail, as emissions fall dramatically with content of biodiesel in fuel blends.