A theoretical analysis was made of the reflected and transmitted waves which were produced when a water-hammer pressure wave encountered a tee in the pipeline. The analysis included the fact that a hydraulic loss existed across the tee. Relationships were developed for determining the magnitude of the reflected and the transmitted waves. However, these relationships were only suitable for the case of instantaneous valve closure, due to the relative magnitudes of the terms involved. An experimental analysis was made in order to verify the theoretical relationships. However, due to malfunctions of the equipment and the ill designed pipeline configuration, very little of the information that was desired could be obtained. Hence, the theoretical analysis could not be verified. / Master of Science

No description available.

No description available.

Thesis (M. Heal. Sc.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (leaves 85-88). Also available via the World Wide Web.

Detta examensarbete har genomförts med anledning av att Norrvatten har önskemål om att få en rapport om de material som används i deras vattenledningsnät med fokus på typiska skador kopplade till ett specifikt material eller tillverkningsmetod. Det har framkommit indikationer om att kunskapen om rörmaterial och dess egenskaper med tiden har försämrats då den äldre generationens projektörer efterlämnat en kunskapslucka efter sig. Syftet med rapporten är att ge en god överblick av materialen i Norrvattens ledningsnät. Det krävs kunskap om materialen för att analysera sambandet mellan läckningsstatistik och materialets egenskaper. Informationshalten varierar mellan de olika materialen. Detta beror framförallt på materialets uppbyggnad och svårighetshalten att redovisa en klar och rättvis bild över dem. Materialen och dess information är uppdelade i kapitel för att underlätta för läsaren att på ett enkelt sätt förstå sammanhangen. Ett annat viktigt kapitel i denna rapport är beskrivningen över de anläggningsmetoder som valdes att tas med, dels markförlagda ledningar men också två schaktfria metoder vilka är infodring och rörspräckning. I verkligheten finns det många fler utbytesalternativ än dem som tas upp i rapporten, men många metoder är snarlika och dem som redovisas tillhör de vanligaste arbetssätten. Detta kapitel är direkt knutet till dimensioneringsverktyget för utbytesmetoderna med avseende på hållfasthet från jordtryck samt trafiklaster, men också dragspänningar som uppstår i framförallt de schaktfria metoderna. Dimensioneringsverktyget består av ett Excel-dokument där användaren med grundläggande parametrar fyller i dokumentet för att sedan få resultat huruvida den nylagda ledningen klarar de påfrestningar som den utsätts för. Baserat på ledningsanvändning mellan olika material och jämföra mot dess skadestatistik vill vi ge en god slutsats om vilket material som vi anser, generellt sett, är lämpligast att använda sig utav. / This thesis has been conducted in response to a request by Norrvatten for an objective report concerning the materials used in their water supply infrastructure, with a focus on the typical damages linked to specific materials or manufacturing processes. Through interviews with well-informed experts we have received indications that the knowledge regarding the materials used in Norrvatten’s water pipes and said materials’ properties have declined over time, as the older generation of construction planners have left behind a knowledge gap. The purpose of the report is to give a good insight into the materials used in Norrvatten’s water supply infrastructure (specifically the pipes used). We claim that a knowledge of the materials used is necessary to analyze the correlation between leakage statistics and the properties of the materials used in the infrastructure. The level of information available varies between the different materials. This is mainly caused by the structure of the material and the difficulty in depicting a clear and objective picture of it. The materials and their information are divided into separate chapters to make it easier for the reader to understand the picture we are trying to create. Another important chapter in this report is the description of the methods of installation we have chosen to work with; these methods are buried pipelines but also two trenchless methods which are lining and pipe bursting. In reality many more methods that the ones described here exist, but many methods are similar and the ones presented here are those that are most commonly used. This chapter is directly linked to our dimensioning model for pipe replacements concerning strength in regard to earth pressure and traffic load, but also the tensile that occur primarily in the trenchless methods. The dimensionality model is constructed as an Excel document where the user – through utilizing some basic parameters – fills out the document and automatically receives results regarding whether or not the new pipes will withstand the stress it is exposed to. Based on the correlation between damage statistics and the use of different materials in the pipe infrastructure we attempt to provide an accurate picture of which materials we deem to be, generally speaking, the most appropriate to make use of.

The subject of the diploma thesis is a design of a spatial and functional concept of the site of non-functional historical reservoirs in Brno on Yellow hill. The aim of the work is to create an idea of the use of the site and its underground reservoirs and to find a strategy for involving the site in the functioning of the city. The source of water was an elementary condition in the expansion and growth of city, and now few people realize how large network of underground structurs ensures its circulation and how important was their role in the past. The main idea of the work is to focus not only on one accessible reservoir in the area on Yellow Hill, but on a wider water world of Brno.

Hållbarhets- och klimatfokus driver aktörer inom bygg- och anläggningsbranschen att utveckla nya arbetssätt och verktyg för att minimera klimatpåverkan från den egna verksamheten. Livscykelanalyser, LCA, som ett miljöledningsverktyg för att analysera och minska klimatpåverkan från processer kräver stora resurser för att applicera LCAmetodik på hela entreprenadprojekt. Ett flertal nischade beräkningsverktyg har därför utvecklats av intressenter inom ledningsrenovering. Som ledningsnätsägare har Norrvatten höga krav på kvalitet vid nyläggning och renovering av huvudvattenledningar. Men även ett miljöfokus och engagemang för nya tekniker som mynnat ut i användandet av nya schaktfria metoder för renoveringsprojekt, ibland i grunden av praktiska skäl men där en betydande minskning av klimatpåverkan kan anses uppstå till följd. Genom större insyn i klimatpåverkan från entreprenadprojekt skapas underlag för framtida beslutsfattande, arbetsprocesser och fortsatta studier. Syftet med studien var att se över tillgängliga beräkningsverktyg och deras användbarhet och användarvänlighet. Vidare att analysera aktuella vattenledningsentreprenadprojekt utförda i öppen schakt samt schaktfri metod för att se om dessa val kan påverka hur entreprenader kan utföras mer hållbart, ur ett klimatmässigt och ekonomiskt perspektiv. Under studien uppstod problem vid resursinventering för entreprenaderna, där faktiska mängder från entreprenörer ej kunde erhållas. Endast övergripande kartläggning och analys utfördes därför av entreprenaderna, i kombination med ett antal beräkningsverktyg tillgängliga på marknaden. Studien visar att många nischade beräkningsverktyg baserade på LCA-metodik saknar anpassning för analys av ledningsentreprenader med större rördimensioner, vanligt förekommande inom Norrvattens ledningsnät. Beräkningsverktyg saknar även den transparens och därmed jämförbarhet som renodlade LCA-verktyg. Resultatet visade dock att, även trots antagen och uppskattad analys av ingående parametrar för projekten, skapades en ganska likartad bild av den procentuella sänkningen av kg CO2-ekvivalenter mellan de olika teknikerna. Den beräknade klimatpåverkan var omkring 80% lägre per meter ledning för påverkanskategori GWP, liknande det resultat som kunde erhållas från nischade beräkningsverktyg. Med hänsyn tagen till att den schaktfria metoden infodring är relativt ny för dricksvattenledningar samt har en halverad teoretisk materiallivslängd kan en teoretisk brytpunkt beräknas till 231,8 år eller drygt fyra schaktfria renoveringar innan klimatpåverkan uppgår till motsvarande renovering i traditionell öppen schakt. Fortsatta studier kan med fördel mer ingående fokusera på resursinventering av entreprenader och fördjupning inom transparenta LCA-verktyg likt miljöberäkningsverktyget, BM 1.0. Alternativt bygga vidare på rapportens analys och beräkningsdel för framtagning av ett nischat beräkningsverktyg. / Sustainability and environmental focus drives actors in the construction industry into developing new working methods and tools to minimize the climate impact from their own activities. Life cycle assessment, LCA, as an environmental management tool for analyzing and reducing the climate impact of processes require considerable resources to apply the methodology to entire construction projects. A number of niche calculation tools have therefore been developed by actors working with trenchless technologies. As a grid owner, Norrvatten has high demands on quality when installing and renovating main water pipes. But also, an environmental focus and commitment to new technologies that have resulted in the use of new shaft-free methods for renovation projects, sometimes for practical reasons but where a significant reduction in climate impact can result. Greater transparency in the climate impact from contracting projects creates the basis for future decision-making, work processes and further studies. The purpose of the study was to review available calculation tools and their usefulness and ease of use. Furthermore, to analyze current projects carried out in open shafts and shaft-free method to see if these choices can affect how contracts can be carried out more sustainably, from a climate and economic perspective. During the study there were problems with gathering information about used resource from the contractors, therefore actual quantities from contractors could not be obtained. Only overall mapping and analysis was carried out, in combination with a number of calculation tools available on the market. The study shows that many niche calculation tools based on LCA methodology lack adaptation for analysis of management contracts with larger pipe dimensions, commonly found in Norrvatten's pipeline network. Calculation tools also lack the transparency and thus comparability as general LCA tools. The result also showed that despite rough assumptions and analysis using several different calculation tools, with different input parameters, a fairly similar picture was created of the percentage reduction in kg CO2 equivalents between the different technologies. The calculated result in climate impact category GPW was about 80% lower per meter pipeline. A similar result that could be obtained from niche calculation tools. Given that the NoDig-method with liner for potable water pipes is fairly new on the market and has a halved theoretical material-lifespan, a theoretical break-even can be estimated to 231,8 years or just over four life cycles of rehabilitation of pipes with the use of this NoDig-technology, before reaching the climate impact corresponding to traditional open shafts. Continued studies can advantageously focus more on resource inventory of contracts and in-depth in transparent LCA-tools like the environmental calculation tool, BM 1.0. Or deeper analysis and further development on a niche calculation tool.

No description available.

Dissertation (PhD)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: Municipal water distribution maintenance is very important for sustainable urban development. Water pipe breaks result not only in a disruption in service but also in significant loss of water, which otherwise could have been sold to the consumer. In countries where water is scarce, such as South Africa, water losses can be detrimental to the living standard of people. Water pipe breaks can furthermore cause extensive damage to nearby lower-lying properties. Existing decision support systems available in the field of water distribution system maintenance are mainly focused on leak detection and pipe rehabilitation/replacement strategy. These existing systems, however, do not address the actual causes of pipe breaks and pipe break impact is also not supported. The aim of this research is to develop a spatial decision support system (SDSS) for pipe break susceptibility analysis and impact assessment. The engineer (or public works administrator) can apply the SDSS to model the complex pipe break phenomena in the municipal water distribution system. The SDSS can identify pipes susceptible to breaking and pipes with potentially high break impact as far as water loss and damage caused to nearby property are concerned. This combined pipe break susceptibility analysis and potential impact assessment should promote more informed decision-making on preventative maintenance measures to be taken and their prioritisation. The dissertation consists offive parts. In the first part (Chapters 1-4) theories on information systems, fuzzy logic, object-oriented modelling, Unified Modelling Language (UML) and pipe break causes are presented. This literature review provides a basis on which the SDSS for pipe break susceptibility analysis and impact assessment can be developed. In the second part (Chapter 5) the general user requirements and design of the SDSS are given. The general SDSS architecture, the general system functionality and the user interface are described and designed in this part of the dissertation. The third part (Chapter 6) provides the detailed user requirements and design of the subsystems of the SDSS. Specialised functionality for pipe break susceptibility analysis and impact assessment is added to the general design of the SDSS. Subsystems are designed for analysing the pipe break susceptibility due to age, air-pocket formation and tree-root attack. Pipe break impact assessment subsystems are also designed for assessing water loss and potential damage caused to nearby property. Finally, a combined analysis subsystem is designed for combined pipe break susceptibility analysis and impact assessment. In the fourth part (Chapter 7), the SDSS is applied to the water distribution system of the Paarl Municipality to identify pipes in the network that have both high break susceptibility and also high break impact. The pipe break susceptibility analysis model of the SDSS is also tested and calibrated by comparing the model results with actual pipe break occurrence data of the study area. The final chapter (Chapter 8) contains the summary and recommendations regarding the functionality of the newly developed SDSS. / AFRIKAANSE OPSOMMING: Die instandhouding van munisipale waterverspreidingstelsels is uiters belangrik vir volhoubare stedelike ontwikkeling. Waterpypbreuke lei nie alleenlik tot onderbreking in diensverskaffing nie, maar ook tot beduidende waterverlies en verlies aan inkomste uit waterverkope. In lande waar water skaars is, soos in Suid-Afrika, kan waterverliese die lewenstandaard van die bevolking nadelig beïnvloed. Waterpypbreuke kan ook groot skade aan naby-geleë laag-liggende eiendomme aanrig. Besluitnemingstelsels tans beskikbaar op die gebied van instandhouding van waterverspreidingstelsels is hoofsaaklik gerig op lekkasie-opsporing en pyprehabilitasie- en pypvervangingstrategieë. Hierdie bestaande stelsels spreek egter nie die eintlike oorsake van pypbreuke aan nie, daar word ook nie op die impak van pypbreuke ingegaan nie. Die doelwit van hierdie navorsing is om 'n ruimtelike besluitnemingstelsel (RBS) - vir pypbreuk-risiko-analise en impakberaming te ontwikkel. Die ingenieur (of stelselbestuurder) kan met behulp van die RBS die komplekse pypbreukverskynsel in 'n munisipale waterverspreidingstelsel modelleer. Die RBS kan pype met hoë breek-potensiaal identifiseer asook pype wat, indien dit breek, groot waterverlies of skade aan naby-geleë eiendomme sal veroorsaak. Hierdie gekombineerde pypbreuk-risiko-analise en impakberaming behoort meer oordeelkundige besluitneming te bevorder deur beter prioritisering van voorkomende instandhoudingsmaatreëls en die uitvoering daarvan. Die proefskrif bestaan uit vyf dele. In die eerste deel (Hoofstukke 1-4) word die teorieë oor inligtingstelsels, 'fuzzy logic', objek-georiënteerde modellering, 'unified modelling language (UML)' en die oorsake van pypbreuke behandel. Hierdie literatuurstudie skep die basis waaruit die RBS vir pypbreukrisikobepaling en impakberaming ontwikkel sal word. In die tweede deel (Hoofstuk 5) word die algemene gebruikersbehoeftes en die ontwerp van die RBS uiteengesit. Die algemene RBS struktuur en die gebruikerskoppelvlak word in hierdie deel van die proefskrif beskryf en ontwerp. In die derde deel (Hoofstuk 6) word die gedetailleerde gebruikersbehoeftes en die ontwerp van die substelsels van die RBS uiteengesit. Gespesialiseerde funksionaliteit vir pypbreuk-risikobepaling en impakberaming is tot die algemene ontwerp van die RBS bygevoeg. Substelsels is ontwerp vir die ontleding van pypbreuk-risiko as gevolg van ouderdom, lugblaas-vorming en boomwortelaanval. Substelsels vir impakberaming is ook ontwerp om waterverlies en potensiële skade aan eiendomme vas te stel. Ten slotte word 'n gekombineerde ontledingsubstelsel vir gekombineerde pypbreuk-risikobepaling en impakberaming opgestel. In die vierde deel (Hoofstuk 7) word die RBS toegepas op die waterverspreidingstelsel van die Paarlse munisipaliteit om pype uit te ken wat beide 'n hoë breuk-risiko en 'n hoë breuk-impak bevat. Die pypbreuk-analise model van die RBS is ook getoets en gekalibreer deur die resultate van die model te vergelyk met data van werklike pypbreuke in die studiegebied. Die laaste hoofstuk (Hoofstuk 8) bevat die samevatting en die aanbevelings rakende die funksionaliteit van die voorgestelde RBS.

Orientador: Michael John Brennan / Resumo: O principal problema em companhias de água são os vazamentos em tubulações subterrâneas, devido a sua limitada fonte de recursos hídricos. Correlacionadores de ruídos de vazamentos são usados frequentemente para localizar vazamentos. A detecção de sinais de ruídos de vazamentos ocorre por meio da coleta de dados por sensores, aos quais estão inseridos em lugares extremos ao da localização de um suposto vazamento. Estes dados são correlacionados, obtendo o atraso do tempo entre estes sinais de vazamento. Para converter o atraso do tempo em distância, a velocidade de onda do ruído de vazamento necessita ser conhecida, frequentemente, este tempo é estimado por meio de dados históricos de velocidade ou por tabelas. Usualmente a velocidade não é medida diretamente pelo tempo, sendo uma potencial fonte de erro. Esta tese estuda os fatores que afetam a velocidade de propagação do ruído de vazamento em tubulações de água subterrâneas. Eles envolvem as caraterísticas do filtrado do sistema sensor-tubulação e a potencial faixa de frequência onde o ruído de vazamento possa estar presente, e o efeito da banda de frequência na estimação do atraso do tempo. Os efeitos de distorção na precisão da estimativa do atraso do tempo, são também estudados com foco na quantização e corte dos sinais de vazamento. O efeito de quantização é devido a um convertedor analógico digital. O corte dos sinais de vazamento acontece quando a amplitude do sinal excede os limites do intervalo dinâmico da instrumen... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor