FACULTY OF INSTALLATIONS. Eng. Ioan Aşchilean. Ph.D. THESIS - ABSTRACT -

Transcription

1 FACULTY OF INSTALLATIONS Eng. Ioan Aşchilean Ph.D. THESIS - ABSTRACT - THEORETICAL AND EXPERIMENTAL CONTRIBUTIONS REGARDING THE REHABILITATION AND MODERNIZATION OF URBAN WATER SUPPLY Thesis Supervisor, Professor Gheorghe Badea, Ph.D. Eng. Ph.D. Thesis Assessment Commission: PRESIDENT: MEMBERS: - Lecturer Carmen MÂRZA, Ph.D. Eng. scientific secretary, Faculty of Installations, Technical University of Cluj-Napoca; - Professor Gheorghe BADEA, Ph.D. Eng. thesis supervisor, Faculty of Installations, Technical University of Cluj-Napoca; - Professor Ioan BORZA, Ph.D. Eng. - referent, Faculty of Constructions, University Polytechnics Timişoara; - Professor Traian CRUCERU, Ph.D. Eng. - referent, Faculty of Installations, Technical University of Constructions, Bucharest; - Professor Theodor Dorin MATEESCU, Ph.D. Eng. - referent, Faculty of Installations and Constructions, Technical University Gheorghe Asachi Iasi. 2009

2 2 TABLE OF CONTENTS (main chapters) Chapter 1. INTRODUCTION Chapter 2. WATER SUPPLY SYSTEMS, REQUIREMENTS REGARDING A DEVELOPMENT ACCORDING TO THE NEEDS OF THE POPULATION Chapter 3. TECHICAL POSSIBILITIES AND CALCULATION METHODS FOR THE REHABILITATION OF WATER SUPPLY SYSTEMS Chapter 4. TECHNICAL AND ECONOMIC STRATEGIES FOR THE SELECTION OF THE BEST METHOD FOR THE REHABILITATION OR THE MODERNIZATION OF WATER SUPPLY SYSTEMS Chapter 5. CASE STUDY ANALYSIS OF THE WATER SUPPLY SYSTEM OF THE CITY OF CLUJ-NAPOCA Chapter 6. PERSONAL CONTRIBUTIONS, CONCLUSIONS, RECOMMENDATIONS References KEY WORDS Criteria, diameter, distribution, efficiency, flow, flow rate, lost head, methods, modernization, multi-criteria analysis, pipes, pressure, project, pumping, rehabilitation, roughness, source, speed, storage/ accumulation, system, treatment, trenchless technologies, water supply system, well

3 3 THESIS OUTLINE This Ph.D. thesis tackles the methods used for the rehabilitation and the modernization of urban water supply systems. Starting off from the global, historical, present, economic and cultural meaning of water resources, this thesis aims to explain the essential speciality concepts and to provide an overall perspective on the legal provisions and standards in force. Water management is currently regarded as a sustainable development in the international context. The topic of this thesis Theoretical and experimental contributions regarding the rehabilitation and modernization of urban water supply includes technical measures aimed at the rehabilitation of installations, taking into account the environmental, social and economic implications. This thesis offers, by particularly emphasizing the reports provided by practical experience, a general overview of the technical procedures of rehabilitation and modernization of urban water supply systems. Furthermore, it analyses from a critical perspective the calculation estimates used in the assessment of the efficiency of these procedures. A thinking algorithm is developed with a view to facilitating the structuring of the urban water supply systems, as a whole, before rehabilitation works are carried out, as well as to joining a set of measures which are optimized from a time, economic and technical point of view. This Ph.D. thesis aims to achieve the following main and secondary objectives: - Main objective: o to establish the technical and economic criteria taken into account when deciding on the rehabilitation and modernization methods for urban water supply systems, so that water become a good accessible to all; - Secondary objectives: o o Chapter 1.INTRODUCTION to define a general methodology for the rehabilitation of pipes using trenchless technologies; to establish the best time for the rehabilitation or modernization of water supply systems. Water has always been a vital element in the life of human society, the settlement and the civilisation having developed in the presence of water resources and often vanishing with the their disappearance or degradation. Water can be both a positive and a negative development factor, it can be either a work means or tool, it is a renewable, irreplaceable resource. Chapter 1 presents the general context, the structure and the objectives of this thesis. Therefore, this chapter highlights various aspects related to water and its importance in various fields, among which it is worth mentioning the following: water as an element which is indispensable to life, for all the organisms and ecosystems, due to its being so wide spread and to its special properties, information on the appearance of water on Earth and where it can be found, the molecular structure of water, the hydrological flow, the issue of adequately providing the population with water on a world scale, the cultural value of water etc. In order to plan the rehabilitation or the modernization of the damaged parts of drinking water supply systems, at least the following questions ought to be answered: - whether it is more appropriate to carry out rehabilitation or modernization works; - which is the best rehabilitation / modernization technology; - when is the best time to carry out rehabilitation / modernization works;

4 4 - which are the technical and economic criteria for rehabilitation / modernization; - which are the elements that must have priority in the rehabilitation / modernization projects. In a graphic format, the structure of the thesis can be depicted as follows: Chapter 2.WATER SUPPLY SYSTEMS, REQUIREMENTS REGARDING A DEVELOPMENT ACCORDING TO THE NEEDS OF THE POPULATION Based on the main statements in chapter 1 on water resources and their availability, as well as on the delimitations presented, the second chapter of this thesis lists the requirements of a development which could meet the needs of water supply for the population. Chapter 2 offers a short overview of the past achievements, of the efforts made by the leaders in Antiquity in order to ensure the maintenance, the rehabilitation and the construction of drinking water systems and the decline of this knowledge once with the fall of the Roman Empire. It analyses the rehabilitation of the catchment of Samos sources and supply main pipeline (6 th century BC), the reconstruction and the extension of the supply main pipeline to Pergamon in the Greek and Roman age and the rehabilitation works performed on Roman aqueducts. Furthermore, it presents information on today s challenges for water supply, starting off from the existing research regarding water supply systems, both on the international level and on the European level. After describing water supply on the world level, this thesis deals with water supply in Romania.

5 5 Chapter 3.TECHICAL POSSIBILITIES AND CALCULATION METHODS FOR THE REHABILITATION OF WATER SUPPLY SYSTEMS Chapter 3 is divided into the four technical fields regarding water supply systems: water catchment, treatment, storage and distribution. Thus, it analyses from the beginning the rehabilitation and the modernization of water catchment installations, placing a particular emphasis on the vertical strainer wells. Starting off from the well aging processes, it explains their cleaning and rehabilitation procedures. The rehabilitation of wells depends on the scale of the damages. The mechanical, hydro-mechanical and chemical cleaning methods can remove incrustations and sanding. In case of construction damage, such as leakages or static problems on the well installation partially due to the geological modifications, a rehabilitation of the well is required. It further presents the rehabilitation possibilities for the water treatment installations. By describing some of the selected projects and innovative treatment procedures, it presents the way how the existing installations can be completed or replaced. The assessment focus will be placed on the filtration procedures. Moreover, it examines how investment decisions can be economically justified. Subsequently, it also presents the rehabilitation of water storage systems. This subchapter presents the possibilities to renew the pumping installations and water storage systems, to rehabilitate and to modernize them. The key point consists in water storage systems, since the costs related to their rehabilitation usually bear a much higher importance than the replacement of water pumps. The rehabilitation procedures will be explained by including some practical examples. It also examines the advantages, the risks, the framework requirements and the technological restrictions. It further analyses the specific costs related to the investment, as well as the operating costs. At the end, this chapter investigates on the whole the rehabilitation and the modernization of water distribution systems. During the last decade, the investments made in the sector of water supply infrastructure, most of them, focused on the extension of the existing networks and the setting up of new networks in areas which, up to then, have not benefited from this facility, in an age when the need to ensure water represents a constant concern and is always a topical issue. The thesis also examines the procedures by which the pipe networks can be assessed, researched and diagnosed (the statistics of damages) and will be compared from the point of view of their usage capacity. Particular attention will be paid to pipe rehabilitation procedures, mainly on the recently developed trenchless technologies. Firstly, it will assess whether the pipes requiring rehabilitation are still stable and sealed. Should their tightness be in a good state, the ratio between the pressures in the pipe line can be optimized by hydraulic calculations? These may be divided into 6 categories: - technologies for the introduction of the new pipeline by deforming its section by bending it in a C shape (Compact Pipe) or in a U shape (U-liner or linear U) or by reducing by force its diameter (swage lining, roll-down). - technologies for the introduction of a new pipeline with a smaller diameter in the old pipe line (Slip-lining); - technologies for the treatment of old pipelines to introduce a textile hose treated with resin/ glass fibres, etc. CIPP (cured-in-place pipe), GFK Liner; - technologies for the replacement of the pipeline by taking the old pipes from the ground Pilot Pipe;

6 6 - technologies used for the expansion the old pipe (In line expansion) Berstlining (Pipe bursting), Microtunneling; - technologies for the punctual treatment of problems (Short-liner, local application of resin/ mortar/ glass fibre etc.) Moreover, this chapter presents the calculation formulae used for the flows and pressure decline corresponding to rehabilitated and modernized pipes. Chapter 4.TECHNICAL AND ECONOMIC STRATEGIES FOR THE SELECTION OF THE BEST METHOD FOR THE REHABILITATION OR THE MODERNIZATION OF WATER SUPPLY SYSTEMS Chapter 4 investigates the rehabilitation possibilities for the pipeline networks, which were developed in order to efficiently shape from a technical and economic perspective the rehabilitation methods. To this end, it will firstly define the context in which the pipe rehabilitation or modernization process is launched and the decision criteria for their rehabilitation or modernization. The decision criteria for the rehabilitation or modernization of the systems in place are numerous and it is difficult to establish precise, universal rules, taking into account the fact that situations differ from one case to another. When making the decision to replace a pipeline, it is paramount to start off from their history. On the other hand, however, the decision maker must take into consideration both the future functional requirements of the system, as well as its estimated life cycle. The key information will allow the preparation of an organised project in order to facilitate the replacing of pipes. It will also take into account the information regarding the pipeline as such, the environment, the hydraulic system and the water quality. Then, the best rehabilitation time will be established and it will examine the estimated life cycle of the pipelines, firstly with the used of certain models in the specialty literature and, then, by using some proper methods. In order to establish the technologies used for the rehabilitation or the modernization which are to be implemented, the chapter presents the multi-criteria analysis methods and it will correctly apply the ELECTRE I method for the rehabilitation of pipes. In order to assess the opportunity of the investment from an economic point of view, as well as to compare all alternative investments, the chapter proposed the application of annuity calculation method, a dynamic procedure allowing the calculation of investments. These methods will be adjusted for the other rehabilitation fields, mainly in the case of pumps, accumulation reservoirs, treatment installations, as well as for the rehabilitation of wells. It further presents the way to define a matrix to be applied to all possible investments, required in the future in a certain urban settlement. The economic comparison of the treatment options allows the definition of a logical and technically harmonized set of measures. This can be transposed into a long-term planning of the budget, in small steps. With the help of the above-mentioned methods, practically in all the fields of urban water supply, it is possible to make optimized rehabilitation decisions from the point of view of their efficiency. Chapter 5.CASE STUDY ANALYSIS OF THE WATER SUPPLY SYSTEM OF THE CITY OF CLUJ-NAPOCA Chapter 5 presents the implementation of a case study regarding the water supply system in the city of Cluj-Napoca, so as the methods presented in this thesis be validated by practical applications.

7 7 This chapter will actually implement the economically and technically optimised decision model defined within this thesis. Chapter 5 concludes with the presentation of the conclusions on the investigated case study. Chapter 6.PERSONAL CONTRIBUTIONS, CONCLUSIONS, RECOMMENDATIONS Chapter 6 presents the personal contributions, the research conclusions and all recommendations for further research. The main personal contributions brought through this thesis are the following: - the development of certain methods used for the establishment of the best time for the rehabilitation or modernization, according to the linear damping, the estimate of the increase of the cost related to the repairing of damages and to the losses in the system and the maximal frequency damage occurrence; - the analysis and the comparison of the trenchless technologies used for the rehabilitation of pipes, according to the material from which the pipe to be rehabilitated is made, the material from which the rehabilitated pipe is made, diameters and lengths; - calculation relations for the flows and the pressure declines corresponding to the rehabilitated and modernized pipes; - applications of the ELECTRE I multi-criteria method when choosing the best technology for the rehabilitation of water supply networks; - the application of annuity method in the calculation of the economic efficiency of rehabilitation methods. The technological development must still be limited by an enhanced awareness of costs. These opposing trends may be countered only by a thorough calculation of costs, which should include the entire system and which should allow the long-term planning of the rehabilitation investment. The technical and economic assessment model presented in this thesis offers a solution to all theses challenges. SHORT BIBLIOGRAPHY 1. Aşchilean, Ioan - Calculation relationships for the flow rates and ressure drops of the revamped and upgrated pipes, Revista Acta Technica Napocensis, Section: Civil Engineering Architecture Nr.52/2009, pag , Cluj-Napoca, Aşchilean, Ioan - Innovative procedures for the removal of iron and manganese - Revista Acta Technica Napocensis, Section: Civil Engineering Architecture Nr.52/2009 ISSN , pag , Cluj-Napoca, Badea, Gheorghe - Instalaţii sanitare, Ed. Risoprint, Cluj-Napoca, Badea, Gheorghe; Aşchilean, Ioan - Necesităţi şi exigenţe privind reabilitarea şi modernizarea sistemelor de alimentare şi distribuţie a apei ȋn localităţi, National Conference Ştiinţa modernă şi Energia, pag , Cluj-Napoca, Bârsan, Emanoil - Alimentări cu apă, Ed. CERMI, Iaşi, Grambow, Martin - Wassermanagement, Ed. Vieweg; Wiesbaden, Karger, Rosemarie; Cord-Landwehr, Klaus; Hoffmann, Frank Wasserversorgung, Editura Vieweg + Teubner, Wiesbaden, Leist, Hans-Jürgen - Wasserversorgung in Deutschland, Ed. Oekonom; München, Ritter, Klaus (Hrsg.) - Praxis der Wasserversorgung, DELIWA Berugsvereinigung für das Energieund Wasserfach e.v., Hanovra, Roscher, Harald - Rehabilitation von Wasserversorgungsnetzen Strategien, Verfahren, Fallbeispiele, Berlin, 2000