市政排水工程中钢筋混凝土管与PVC-U管的选用

近年来,国内对管道的材质要求越来越严格,投入大量资金进行开发和研究工作。一方面管材选择是技术经济比较的结果,另一方面管道本体材料对管内水质的二次污染影响很大,对于水中碳酸钙(镁)的结垢,水中溶解性铁离子氧化对管道的腐蚀、结垢,以及一些生物性的堵塞等状态,往往也是选择管材另一重要因素。该文结合实际工作经验,就钢筋混凝土管和硬聚氯乙烯(PVC-U)管在排水工程中的设计进行了研究和探讨,并提出了施工注意事项。     

落地梁的设计浅析及应用前景

该文以某地矿坑匝道落地梁桥为例,简述落地梁在实际工程中应用时的优缺点及应用前景。同时,应用通用有限元程序(SAP2000)对落地梁的正常使用状态和承载能力极限状态进行计算分析。其主要结论对该桥型的设计有指导性意义。     

A suppressed demand analysis method of the transportation disadvantaged in policy making

Abstract

This paper proposes a method for estimating transportation supply requirements when the suppressed demand of the transportation disadvantaged (TD) can be calculated and added to existing demand for travel. The underlying assumption is that the travel conditions of these TD groups must be equal to the ‘conventional’ demand, known as ‘full release’. Utilising the modelling approach for TD, suppressed demand analysis, diagnosis of difficulties and equity between conventional and disadvantaged groups were realised, while elaborating special cases for the most vulnerable TD groups (such as elderly and disabled persons) and simultaneously identifying areas of difficulty. From the early virtual results, it is concluded that, for the full release of suppressed trips (only a 5% increase), policy makers must be ready to face some financial burdens, requiring coordination of effort to both standardise these TD groups and reduce the costs incurred by operators.     

Promoting social inclusion in a deregulated environment: Extending accessibility using collective taxi-based services

Bus based public transport has enjoyed revitalisation in many urban areas but outside large towns and cities its provision and quality remains erratic. Many rural settlements have infrequent services giving rise to social exclusion through transport disadvantage.The UK Government highlighted a need in Towards a Sustainable Transport System (2007) for radical new thinking on rural accessibility to help meet goals of quality of life and accessibility for all and to help meet the challenge in finding carbon friendly ways of meeting rural transport needs. This paper reports work undertaken for the Commission for Integrated Transport, an advisory body to UK Government, on how shared taxi-schemes could be developed within a deregulated environment to meet rural accessibility needs. This is based on an analysis of institutional barriers and comparison between successful mainland European schemes and UK schemes. The paper considers economic viability and the levels of subsidy currently used to provide accessibility in rural areas to show the potential for making current expenditure on rural transport in the UK ‘work harder’ to deliver a collective taxi-based service as part of the public transport mix so as to increase rural accessibility.     

变频调速技术在M10T-30m型门机上的应用

介绍了新技术—变频调速控制系统,阐述该技术在门机旋转、变幅机构上应用的可行性及技改前后的优缺点,论证其具有一定的技改价值。     

Modelling the relationship between travel behaviours and social disadvantage

The purpose of this paper is to model the travel behaviour of socially disadvantaged population segments in the United Kingdom (UK) using the data from the UK National Travel Survey 2002–2010. This was achieved by introducing additional socioeconomic variables into a standard national-level trip end model (TEM) and using purpose-based analysis of the travel behaviours of certain key socially disadvantaged groups. Specifically the paper aims to explore how far the economic and social disadvantages of these individuals can be used to explain the inequalities in their travel behaviours.The models demonstrated important differences in travel behaviours according to household income, presence of children in the household, possession of a driver’s licence and belonging to a vulnerable population group, such as being disabled, non-white or having single parent household status. In the case of household income, there was a non-linear relationship with trip frequency and a linear one with distance travelled. The recent economic austerity measures that have been introduced in the UK and many other European countries have led to major cutbacks in public subsidies for socially necessary transport services, making results such as these increasingly important for transport policy decision-making. The results indicate that the inclusion of additional socioeconomic variables is useful for identifying significant differences in the trip patterns and distances travelled by low-income.     

轨道式龙门起重机旋转集装箱形式的探讨

以选择具有旋转机械功能的铁路堆场轨道吊为出发点,对可以实现集装箱旋转功能的现有几种类型轨道吊的优缺点进行分析,并针对我公司铁路堆场布置及装载货物的实际情况进行探讨,最终选择适合我公司的轨道吊。     

Investigating links between transport disadvantage, social exclusion and well-being in Melbourne - Updated results

This paper updates results of an international study aimed at quantifying the links between transport disadvantage (TD), social exclusion (SE) and well-being (WB) in Melbourne, Australia. The study extends knowledge associated with SE and transport by quantify social and behavioural implications of lack of public and private transport and the nature of the social WB benefits associated with improving services.Study aims and methodology are outlined. Recent findings covered relate to car ownership on the urban fringe, patterns of transport disadvantage, the analysis of time poverty related to transport disadvantage, measuring the economic value of additional mobility and use of a Structural Equation Model (SEM) to relate WB and SE to TD and a series of explanatory factors.Overall results suggest that those without a car on the urban fringe adjust well with their circumstances by living close to activity centres. They demonstrate sustainable choices, trading off budgets and home location to balance mobility and accessibility. Poorer households with high car ownership value mobility and cheaper more remote fringe dwellings but demonstrate numerous strategies to reduce high car costs which are acknowledged as a significant burden. Analysis identifies 4 key types of transport disadvantage including a ‘vulnerable/impaired’ group which should be of much greater concern for targeted policy than others due to poor scoring on SE and WB scales. The economic value of new mobility is also explored with results suggesting $AUD 20 per average new trip which is four times larger than conventional values for generated travel.Analysis has also suggested that transport disadvantage can relate to socially advantaged as well as socially disadvantaged groups through time poverty. This was found to be an important mitigating factor when relating TD to WB. A statistically reliable structural equation model is developed suggesting the SE-WB link is strong (−.87) with a modest link between TD-SE (.27).Areas for future research in the project are also summarised.     

洋山深水港三期工程码头伸缩缝设置的优缺点分析

介绍洋山三期码头伸缩缝的构造及改进型伸缩缝橡胶条应用取得的较好效果.分析洋山深水港三期码头伸缩缝的优缺点;根据实测资料研究,对高桩码头伸缩缝宽度、凹凸齿坎宽度、齿坎结构加强提出相应改进建议.可供高桩码头设计和规范修订参考.