U型折叠内衬在燃气管道修复中应用的技术总结

1 U型折叠内衬施工的原理 通过确定要修复管道的准确内径,定制所需要的HDPE管,该管道外径要与要修复管道的内径相匹配,用压管机将已连接的HDPE管冷压成U型,使HDPE管的横截面积减少30%～40%,为了保持U型,用缠绕带将U型管缠紧,通过液压牵引机,牵引入旧管道内并准确定位,对HDPE管两端进行翻边处理,使其与管端法兰相配合,最后用压缩空气将缠绕带胀断,HDPE管恢复原形,使内衬管与外管紧紧地贴合在一起,形成管中管的结构,使得修复后的管道,同时具有钢管与PE管的综合性能,以达到修复旧管的目的.     

燃气管道非开挖更新改造技术的应用研究

介绍PE管插入法和PE折叠管内衬法两种非开挖施工工艺,结合实际工程分析PE管穿管中PE管道与原金属管道连接以及PE管道与PE管道之间连接存在的问题及原因,提出解决方案:在PE管道的段与段之间连接处以及PE管道与原金属管道连接处安装柔性限位器,将柔性限位器及其两侧一定长度的管道浇筑于混凝土支墩中,混凝土支墩直埋于土壤中。     

PE折叠管内插法在燃气管道非开挖改造技术中的应用

相对于传统开挖技术来说,PE折叠管内插法有许多优势,其应用是时代的必然产物。主要介绍各类PE折叠管内插法施工的技术、优缺点,PE折叠管管材的选取、现场复圆工艺、工程应用及其效益分析。     

“U”型穿插PE管非开挖更新埋地管道

市政埋地管道采用非开挖更新势在必行,文章结合工程范例介绍“U”型穿插PE管施工的工艺过程,论证了该工艺的社会和经济效益。     

U型油气分离管回收凝析油技术研究

安塞油田为回收有毒的凝析油,开展了利用U型油气分离管回收凝析油的技术试验。文章介绍了U型油气分离管的结构及工艺特点,结合井组试验情况,对U型分离管试验效果进行了评价。通过安装U型分离管大大提高了凝析液分离效果,简化了井场工艺流程,降低了职工的劳动强度。该U型分离管实现了凝析油的密闭回收。     

PE管穿插法修复城市天然气管道的探讨

论述了PE管穿插技术及其实施方案。比较了换新钢管方案与PE管穿插方案的费用,论证了PE管穿插技术的经济效益和社会效益,探讨了PE管穿插技术的应用范围和前景。     

PE给水管道在城市管网中的应用

从PE管的管材价格和特性，介绍了PE管的优越性及PE管的连接方法，并阐述了PE管在城市道路下的综合地沟内、导向钻技术中的应用，提出PE管施工中应注意的问题。     

PE管不停输开孔封堵技术探讨

介绍传统PE管封堵技术存在的局限性,探讨了PE管不停输开孔封堵技术的技术原理、设备和作业流程.     

PE管在燃气中低压管网工程中的应用

在燃气中低压管网工程中应用PE管的优势越来越受到大家的关注。介绍了PE管的特性,并且对PE管、钢管、球墨铸铁管这三种管材从材料费和施工费两方面进行了比较,得出PE管性能均优于钢管和球墨铸铁管。相信在不远的将来,随着施工技术和人员素质的全面提高,PE管会在城市燃气的中低压管网中发挥越来越重要的作用。     

武汉某地源热泵空调系统埋管部分施工

本文介绍了武汉某地源热泵空调系统中的地埋管部分施工的全过程,包括垂直钻孔、下管、灌浆回填、垂直PE管与水平PE管的连接与敷设,同时对地埋管的施工方法、技术要点和技术措施也进行了相应介绍.     

国家标准《通风与空调工程施工规范》简介

介绍了标准的编制背景、思路和创新点。该标准主要内容包括施工管理,风管与配件、风阀与部件及支吊架等的现场制作与安装,水管道和设置安装以及试验与调试方面的规定。该标准的规定解决了施工安装中的一些共性问题。     

Landscape Dynamics and the Management of Change

Change in economy and society is directly reflected in the character of landscapes, both in terms of their form and function and the landscape planning and management challenges which they present. The phenomenon of landscape dynamics within post-industrial society is considered and the development of a connection between the drivers of landscape change and the management response is sought. Two key drivers of landscape change are proposed - 'obsolescence' and 'dysfunction' - and these in turn are related to a management matrix bounded by axes of condition and character of landscape. It is suggested that the definition of these relationships helps to substantiate and more clearly define the tasks of landscape planning, design and management in the United Kingdom.     

景观延续与重塑的人文之道——记安亭中学绿化环境改造更新

校园作为城市公共设施体系中的重要组成部分,对人们的社会生活和精神文明起着重要的影响、教育、服务作用。结合安亭中学的景观改造工程实例,从校园的区位环境因素、历史文化积淀、园内景观现状等方面,分析了改造的必要性,改造工作的原则及人文理念的改造方法,重点阐释了对原有历史和景观的发现、挖掘、保护、改造和再利用。通过简洁、现代的手法,把新景观融入校园的建筑环境、历史环境和人文环境之中,重建具有视觉、生态和文化三重效益的校园景观,把校园环境变成凝固的诗、流动的画、无言的歌,从而达到"润物细无声"的效果。     

Designing Whole Landscapes

A whole-landscape approach is critical to ensuring conservation and enhancement of biodiversity in farmed landscapes. Although existing agri-environmental schemes are constrained by property boundaries and voluntary take up, the potential for adopting a whole-landscape approach to planned countryside management is currently favoured by a number of factors. These include economic uncertainty in some agricultural sectors; the introduction of a reformulated rural development policy; increased understanding of relationships between biodiversity and management; and the introduction of Geographical Information Systems (GIS) technology that allows future landscapes to be visualized by stakeholders. Ecological and socio-economic aspects of whole-landscape planning in a study covering 31 neighbouring farms in west Oxfordshire are reported. A baseline was first compiled that included information on: property boundaries; land cover; relationships between hedge and field margin management and key taxa; and farmer socio-economics and attitudes towards agri-environmental measures, conservation and sustainable agriculture. Future scenarios of integrated wholelandscape management were then developed, designed to deliver amenity, environmental and biodiversity benefits. These scenarios were presented and interpreted to farmers and conservation and amenity stakeholders with the aid of GIS-based maps and three-dimensional virtual reality visualizations. Farmers' responses are reported and the potential for implementing whole-landscape planning is discussed .     

身体经验与时空想象—— 基于场地、场景、场域的景观建构原型研究

Contemporary landscape is an important medium that resists the environmental homogeneity and diversifies the cultural imagery. The neglect of physical experience would intensify the perception contradiction and separation between people and the site. This paper proposes to use the prototype of the interactions between the body, time, and space to build an abstract discourse to study the design dimensions of site, sight, and insight based on different elements—the three dimensions are represented as perception, conception, and live. It then focuses on how to employ design methods (including the arrangement of spatial sequence and direction, the design of thresholds in the space, the creation of texts and syntaxes, and the stimulation of events and social imagery) to form the push-pull movement in the material space, the abschattung and gestalt of ideographic texts in the meaning space, and the apperception of the social field, so as to enhance people’s perception of the landscape. This paper studies physical experience and spacetime imagery to extract and deduce the thinking of landscape design within varied dimensions, and argues that a profound and intimate relationship between man and the site can be established by organizing different elements under the ternary system of site, sight, and insight.     

Limit states design in geotechnical engineering

The paper outlines the ultimate and serviceability limit states in geotechnical engineering practice. The magnitude of conventional partial and total safety factors in earthworks, earth retaining structures and foundations are discussed in terms of the reliability of the subsoil and loading conditions and the probability and seriousness of failure of the structure during its service life. The serviceability of structures and foundations are treated on the basis of empirical damage criteria related to relative rotation and deflection ratios of foundations supporting different types of buildings and engineering structures.     

The Reflection of Medusa: A Review of The City of Imagination

The lately published The City of Imagination by Valerio Morabito challenges the pictorial idea of landscape interpretation and explores the possibilities of storytelling to read and represent the landscape that focuses on the literary and communicative aptitudes of Landscape Architecture. The article reviews the book from the perspective of history, epistemology, method, and reception regarding its literary root, which is notably inspired by Italo Calvino. The review consists of four sections: First, word and image: the historical exemplars of landscape representation between pictorial and verbal tradition. Second, memory and foresight: the authenticity of travelogue and Morabito’s method of working with his travel memories. Third, truth and myth: how Morabito applies the cognitive imperfection in storytelling to his empirical approach that counterbalances the positivist reading of the landscape. And fourth, form and language: the tension between the formal autonomy and the bardic tradition in the visual language of Morabito. The article approaches and further opens the essential dialogues between the palpable existence and fictive landscape, the interpretation and consumption of the thick meanings in human inhabitation, and the cognitive antinomy and reconciliation of positivist and humanistic stances in the discipline.     

用自己的方式祈祷--当代中国风景园林规划设计的挑战

现代中国风景园林处在全球化与区域主义的矛盾、传统和现代的矛盾之中,面临着文化、科技和生态三方面的挑战。只有用包容的心态去了解其他国家的文化,用严谨的态度对待自己的传统和文明,才能在全球化的背景下,在现代文明的冲击下,形成真正有中国特色的当代园林。     

Over-parameterised, uncertain 'mathematical marionettes' - how can we best use catchment water quality models? An example of an 80-year catchment-scale nutrient balance

The Integrated Catchment Model of Nitrogen (INCA-N) was applied to the River Lambourn, a Chalk river-system in southern England. The model's abilities to simulate the long-term trend and seasonal patterns in observed stream water nitrate concentrations from 1920 to 2003 were tested. This is the first time a semi-distributed, daily time-step model has been applied to simulate such a long time period and then used to calculate detailed catchment nutrient budgets which span the conversion of pasture to arable during the late 1930s and 1940s. Thus, this work goes beyond source apportionment and looks to demonstrate how such simulations can be used to assess the state of the catchment and develop an understanding of system behaviour. The mass-balance results from 1921, 1922, 1991, 2001 and 2002 are presented and those for 1991 are compared to other modelled and literature values of loads associated with nitrogen soil processes and export. The variations highlighted the problem of comparing modelled fluxes with point measurements but proved useful for identifying the most poorly understood inputs and processes thereby providing an assessment of input data and model structural uncertainty. The modelled terrestrial and instream mass-balances also highlight the importance of the hydrological conditions in pollutant transport. Between 1922 and 2002, increased inputs of nitrogen from fertiliser, livestock and deposition have altered the nitrogen balance with a shift from possible reduction in soil fertility but little environmental impact in 1922, to a situation of nitrogen accumulation in the soil, groundwater and instream biota in 2002. In 1922 and 2002 it was estimated that approximately 2 and 18 kg N ha^− 1 yr^− 1 respectively were exported from the land to the stream. The utility of the approach and further considerations for the best use of models are discussed.     

南水北调中线膨胀土/岩微观特征及其性质研究

对南水北调中线工程典型的强、中膨胀土/岩开展室内土工试验与X射线衍射试验,研究了其矿物成分及与胀缩性指标的关系,利用扫描电镜SEM图像进行了微观结构的定性分析,并基于MATLAB软件对孔隙和微结构单元体的微观特征进行了定量化研究,探讨了不同类型膨胀土/岩的颗粒形态、结构类型、裂隙分布等微观特征及其与工程特性的关系。结果表明：膨胀土/岩中的蒙脱石等黏土矿物含量高,强膨胀土/岩以絮凝结构,扁平状聚集体与卷曲片状颗粒为主,中膨胀土/岩以紊流状、粒状堆叠结构为主,片状聚集体与单粒体并存,前者微裂隙发育且定向性明显,孔隙比大,孔隙分形维数与颗粒尺寸小于后者。膨胀土/岩微结构单元圆形度低,复杂度高。膨胀岩定向排列特征显著,颗粒分形维数小,颗粒分形维数与膨胀潜势和孔隙比的变化规律一致。微观组分和结构特征与物性指标分别呈线性关系与负指数幂关系。