艰险山区铁路隧道弃碴经验总结与工程实践

文章总结了西部艰险山区的弃碴场种类和不同类型的弃碴场防护措施设计,其中防护措施包括工程防护措施及生态防护措施,同时,以叙永至毕节铁路斑竹林隧道、下坪隧道及下坪车站站场弃碴场为工程案例,介绍了该弃碴场科学正确合理的弃碴方式,并提出了相应的弃碴建议,本文总结所得到的结果可以为类似隧道工程提供参考。     

重丘陵地区沟道型隧道弃碴场稳定性研究

弃碴场稳定性不同于一般的岩土质边坡,其稳定性主要取决于弃碴的物理力学性质、地基岩性、弃土工艺、挡护措施以及边坡高度和水文地质条件,所以分析弃碴场边坡的稳定性是一个综合性问题。文章以长岭隧道斜井弃碴场为例根据弃碴场高度、方量等堆置设计方案以及周边环境,分析选址合理性和碴场级别。从地形地貌、工程地质、水文气象、堆碴设计方案,对堆碴后进行渗流稳定性分析、在天然工况和暴雨工况下泥石流易发程度进行分析。最后利用渗流分析软件Gezeep和极限平衡分析软件Geo-slope计算出碴场边坡的局部和整体的稳定性安全系数,并分析碴场的稳定性状况。     

钢碴地基上建房的实例

钢碴是钢铁工业的废料,它具有很强的膨胀性。上海宝钢采用钢碴桩,利用其膨胀性能加固软弱地基获得了成功。在我市以钢碴代替粘土作回填料,或用作新填地基,由于对其膨胀性能和影响认识不足,技术措施不力,不少工程曾出现问题,地面起鼓、地圈梁断裂外移或墙体开裂倾斜,造成工程拆除、加固,或挖掉回填的钢碴。但     

一种隧道出碴车辆回转平台的研制与应用

为了提高隧道出碴车辆的运输效率,解决隧道内出碴车辆的调头问题,研制了出碴用新型调车平转桥。通过对该设备的设计、制造以及重要部件与关键技术进行的详细描述,结合实验与工程应用实例,介绍了整个隧道出碴车辆调头设备的应用情况。     

谈无碴轨道在装卸煤铁路站场的应用

结合具体工程实例,对无碴轨道在装卸煤铁路站场的应用进行了研究,简要介绍了无碴轨道的优缺点,着重对整体道床的设计进行了详细阐述,以期推动无碴轨道在我国矿区铁路的应用。     

CRTS—Ⅱ型板式无碴轨道施工成套设备国产化研制

京津城际轨道交通工程是我国第一条设计时速350km／h的客运专线,是我国铁路跨越式发展的标志性和试范性工程,同时也是2008北京奥运会工程。工程建设要求实现”三个一流“（一流的施工技术、一流的技术装备、一流的运营管理）的质量目标和2008年8月1日开通运营的工期目标。该工程首次引进德国博格板式无碴轨道系统（国内命名为CRTS—Ⅱ型板式无碴轨道,以下简称”无碴轨道“）。中铁二局承建京津城际轨道交通工程第一先行段,该项目有如下特点：     

浅谈沥青水泥砂浆搅拌车

作为奥运标志性工程的京津城际轨道交通工程,是沟通北京、天津两大直辖市的快速便捷通道,也是我国第一条高速客运专线.该工程采用德国博格公司的板式无碴轨道结构,此博格板式无碴轨道系统为德国联邦铁路署(EBA)批准采用的一种预制板式轨道结构类型.     

隧道工程中无碴轨道道床施工技术探讨

未来高铁建设的主要发展方向就是无碴轨道。随着科技水平的不断提升,国内无碴轨道施工技术也日渐成熟,但无碴轨道整体道床的施工还需要进一步的探索和完善。本文结合具体工程,深入研究并介绍了无碴轨道施工过程中的技术要点,以取得良好的施工效果。     

成组道岔一次性更换优质道碴施工工艺

针对道岔道床存在的污染病害问题,探讨了铁路道岔全断面人工更换优质道碴的施工情况,提出了污染道岔的换碴施工方法以及道岔换碴施工的技术要求,收到了良好的运营效果,以供类似工程参考借鉴。     

长距离大直径盾构隧道无碴道床砼浇筑技术

以莞惠城际轨道交通项目工程12标段大直径盾构隧道无碴道床浇筑工程为例,主要论述如何快速有效在长距离大直径盾构隧道内完成无碴道床砼浇筑施工,针对砼浇筑施工中遇到的难题,提出了具体的解决对策,为今后的长距离大直径盾构隧道无碴道床砼浇筑施工提供借鉴。     

Development of a shrouded wind turbine with a flanged diffuser

We have developed a wind turbine system that consists of a diffuser shroud with a broad-ring flange at the exit periphery and a wind turbine inside it. The flanged-diffuser shroud plays a role of a device for collecting and accelerating the approaching wind. Emphasis is placed on positioning the flange at the exit of a diffuser shroud. Namely, the flange generates a low-pressure region in the exit neighborhood of the diffuser by vortex formation and draws more mass flow to the wind turbine inside the diffuser shroud. To obtain a higher power output of the shrouded wind turbine, we have examined the optimal form of the flanged diffuser, such as the diffuser open angle, flange height, hub ratio, centerbody length, inlet shroud shape and so on. As a result, a shrouded wind turbine equipped with a flanged diffuser has been developed, and demonstrated power augmentation for a given turbine diameter and wind speed by a factor of about 4-5 compared to a standard (bare) wind turbine. In a field experiment using a prototype wind turbine with a flanged diffuser shroud, the output performance was as expected and equalled that of the wind tunnel experiment.     

开孔板连接件相对滑移机理试验研究

为研究组合结构桥梁中开孔板连接件的相对滑移机理,以开孔板厚度、孔中钢筋直径、开孔板孔径为变化参数,进行了21个开孔板连接件抗剪性能模型试验。通过理论分析与试验结果比较,揭示了开孔板连接件相对滑移量主要由孔中钢筋剪切变形量、孔中混凝土压缩变形量和剪切变形量三部分组成,以及抗剪承载力对应相对滑移量随板厚增加而减小,随孔径、孔中钢筋直径增加而增大的滑移机理。     

Inside the Eco-home: Using Video to Understand the Implications of Innovative Housing

As a method of qualitative research, video offers a means of looking into the world of a respondent and a means of stimulating a dialogue, both with the respondent and others. Video requires, however, the application of additional ethical procedures and may also increase refusal rates, if it is publicly disseminated. Applied to the home, the use of video reveals both practice and identity. Video records practice, showing how the spaces within a home are used at a particular time. For this reason, video is well adapted to understanding the implications of living in a home with an innovative design and technology, with all the complexities that this commonly involves. Equally, video communicates the appearance of the home and of its occupants to whoever is watching. Video is, therefore, intimately connected to identity and the home as a place.     

Time to build options in construction processes

Time to build is a very important factor in a real estate development venture. Delay in completion of a project not only affects the financing costs and the rental revenue but also it may, on a more strategic note, determine the success or failure of a project. A time to build option model consisting of a stochastic rate of completion and a stochastic net project payoff is applied to the sequential construction process of a large scale construction project. The results of the sensitivity analysis show that the optimal payoff value, that triggers the exercise of the option to invest at a maximum rate, increases positively with the increases in cash flow volatility, input cost uncertainty, excess asset return per unit risk and maximum rate of investment. However, it has a negative relationship with the rental yield. In a case study involving a commercial project, the premium for hedging the payoff risks by pre-leasing a project was estimated at 11.29%, whereas the additional cost incurred for shielding a project against input cost risks in a design and build contract was estimated at 7.80%, where each is given as a percentage of the total construction costs.     

横向流动土体作用下的群桩反应性状

借助FLAC3D程序,分析了基坑开挖后土体横向流动作用下坑内群桩的反应性状。研究了两桩、四桩、五桩、六桩群桩中基桩的反应性状,并与相同位置的单桩反应进行了比较,得到了受横向流动土体作用的群桩相互作用规律:桩基连线平行于边坡布置的两桩,相互影响并不明显;而在其它情况下,前排桩对后排桩遮拦、后排桩对前排桩阻挡,均使受影响的桩基内力分布改变,桩身最大变形量减小;受周围越多、越近桩基的影响,基桩的内力和变位减少得越多。根据桩间土体的成拱特征,定性解释了群桩相互作用的机理与规律,具体工程的现场量测结果也验证了此结论。     

Choctaw Eco-Industrial Park: an ecological approach to industrial land-use planning and design

This project investigates the concepts of industrial ecology and eco-industrial parks and applies those concepts to the redesign of an existing industrial park in Choctaw, OK. The opportunity for developing an eco-industrial park on this site comes from the availability of waste water for non-potable water needs, and the abundance of waste tires as raw materials for products to drive a new set of industrial partnerships. These industrial partnerships include the City of Choctaw Waste Water Treatment Plant, a tire shredding company, a tire pyrolysis company, a hydroponics industry, a hard rubber tire manufacturer, a screen printer, a plastics manufacturer, a toner manufacturer, and a toner cartridge manufacturer. The nature of this relationship and the design of the eco-industrial park is contained within this report. The result of this investigation is a new, common sense, approach to industrial land use that combines economic growth and environmental protection.     

Nonlinear analysis and reliability of metallic truss structures

The present study goes into the search for the safety domain of civil engineering structures. The objective is to show how a reliability-evaluation brought by a mechanical sizing can be obtained. For that purpose, it is necessary to have a mechanical model and a reliability model representing correctly the behavior of this type of structure.It is a question on one hand, to propose a formulation for the nonlinear calculation (mechanical nonlinearity) of the spatial structures in trusses, and on the other hand, to propose or to adapt a formulation and a modeling of the reliability. The principle of Hasofer-Lind can be applied, in first approach, for the reliability index estimation, scenarios and the probability of failure.The made check concerned metallic in truss structures. Finally, some structures are calculated using the method adapted by Hasofer-Lind to validate the probability approach of the reliability analysis.     

Energy landscape: Los Angeles Harbor and the establishment of oil-based capitalism in Southern California, 1871–1930

In the first three decades of the twentieth century, the Los Angeles metropolitan area emerged as the fastest growing urban–industrial economy on the Pacific Coast. This was a significant achievement for a city without a natural harbour. Despite formidable barriers presented by physical geography, the gradual development of a deep-water harbour in Los Angeles was fundamental to the emergence of oil-based capitalism in Southern California. In the first three decades of the twentieth century, under the municipal governance of a Board of Harbor Commissioners, private oil companies developed Los Angeles Harbor into a modern transhipment facility comprising infrastructures and technologies dedicated to the efficient transportation, storage, and refining of petroleum and petroleum-based products. From this perspective, Los Angeles Harbor needs to be understood as a long-term, fixed-capital investment into oil-based energy as fuel for industry and transportation. As a transhipment facility, Los Angeles Harbor also functioned as a critical outlet for surplus energy after the discovery of several large fields in the Los Angeles Basin in the early 1920s. By focusing on a particular built landscape, this paper aims to contribute insight into how geographies of fixed-capital investment play a role in the regional dynamics of energy transition and establishment.     

Memory,narrative and display – city museums in recent initiatives and debates

Currently, the study and the exhibition of the history and artistic traces of city development are gaining new interest. Several Italian and European cities are proposing, or have just established, organisations or museums intended to ‘display’ their past. Recently a research group has been constitued at the University IUAV of Venice based on the premiss that a contemporary City Museum has to be a conduit for knowledge to a large and varied public including, on equal terms: citizens, immigrants, tourists and people with cultural and professional interests in the urban environment. In this sense Venice seems to be a very good clase‐study. While an important initiative, such as the constitution of a new Museum of the twentieth century in Mestre (the mainland of Venice) is going on, the research group thinks that this kind of institution, within the framework of a very complex and rich system of museums, such as the Venetian one, could have a wide remit. In fact, one of the special key issues for Venice in the twentieth century has been opening up its cultural and productive activities to the external world. Foreigner visitors, as well as many citizens have always had the vision of Venice as a medieval and renaissance city with a very old historical centre. Yet in the course of the twentieth century, the urban settlement had greatly changed in a very interesting and innovative way. This has to be explained and shown to both tourists and the Venetians.     

Data collection and analysis of the building stock and its energy performance—An example for Hellenic buildings

The process of building labeling and certification in accordance to the provisions of the European Directive on the Energy Performance of Buildings (EPBD) constitutes a unique opportunity for collecting information on the characteristics of the building stock and its energy performance on a national and European level. Thus, there is a need to handle data from a large stock of buildings and to be able to analyse information and extract practical trends and benchmarks. Stakeholders and technical managers who oversee a number of buildings experience similar needs in order to collect, organize and monitor the energy performance of a large pool of buildings. To facilitate these efforts, a common evaluation database and complimentary software for its exploitation have been developed in the frame of a European project.This paper presents an overview of the database and its available tools, and the main results from a case study on Hellenic buildings that reveals relevant characteristics. The Hellenic database included a sample of 250 buildings from different regions in Greece, with a breakdown that is representative of the national building stock. The main results focus on the buildings’ energy performance, thermal envelope characteristics and the exploitation of solar thermal energy.