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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

A study of causes of delay and cost overrun in office construction projects in the eThekwini Municipal Area, South Africa

Adugna, Nafkote Tesfahun January 2015 (has links)
Submitted in fulfillment of the academic requirements for the degree of Master of Technology in Construction Management, Durban University of Technology, Durban, South Africa, 2015. / On-time completion and conformity with assigned cost of every project are the most important factors in the success of project plans. Cost overruns and time overrun (delays) have been critical problems of many projects around the world in general and in South Africa in particular. The main objectives of this research are to assess the dominant causes of cost and time overruns, identifying possible and practical measures that can minimize overruns in office building construction projects around eThekwini Municipal area of Kwazulu-Natal. These objectives are achieved through the implementation of the research methodologies that are mainly literature review and questionnaire survey conducted to identify and evaluate the significant factors contributing to delay and cost overruns within the projects of interest. A review of literature identified eighty-five variables for delay, grouped in nine major categories and nine variables for cost overruns ranked in their order of importance in three sets based on the responses from the professionals working for the client, consultants and contractors. The agreement among the sets of rankings for delay and cost overruns has also been tested using statistical methods. The result indicates that there is strong agreement on ranking the importance of the individual variables of delay and cost overruns between parties. From each of the three sets of rankings, the twenty most important variables of delay and the three most important variables of cost overrun are identified as critical. Based on overall results, the top five most important causes are contractor’s cash flow problems, delay in progress payments by the client, poor site supervision and management by contractor, inefficient quality control by the contractor during construction leading to rework due to errors, and contractor’s difficulties in financing the project. Out of the 20 most important delay causing variables, three are found to be common between all parties. These are delay in progress payments by the client, delay in delivery and late ordering of material, and insufficient skill of labour. Furthermore, the study reveals that all stakeholders of construction parties are deeply involved in contributing to the causes of the problems. Thus, in order to eliminate or minimize cost and time extension of office construction projects in the eThekwini Municipal area, a joint effort based on teamwork is essential through effective project planning, controlling and monitoring which boils down to putting in place best practice construction project management.
72

Sustainable cooling alternatives for buildings

Vorster, Jacobus Adriaan 03 1900 (has links)
Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The thesis was initiated by a Consulting Engineering Company (KV3) as a research project to investigate various options in which the efficiency and energy utilisation of conventional air conditioning systems may be enhanced by using alternative and renewable energy. Initially, eight options had been identified and through a process of determining the degree of commercialisation the alternative options were reduced to three. These options, referred to as the sustainable cooling alternatives, are active mass cooling, night flushing and roof cooling system. The roof cooling system comprised a roof-pond, roof-spray, pump and storage tank. The roof cooling system was mathematically and experimentally modelled. The roof cooling experiment was performed under a variety of weather conditions with the roof-pond and storage tank temperatures continuously recorded. The experimentally recorded temperatures were compared to the temperatures generated by the theoretical simulation calculations for the same input and weather conditions. Good agreement was found between the mathematical and experimental model. The largest discrepancy found between the simulated temperature and the experimental temperature was in the order of 1 ºC. A one-room building has been assumed to serve as a basis to which the sustainable cooling alternatives could be applied to for theoretical simulation. The one-room building had four façade walls and a flat roof slab. Night flushing, active mass cooling and the roof cooling system were applied to the one-room building such that the room air temperature and space cooling load could theoretically be simulated. The theoretical simulations were also repeated for the case where the roof-pond and roof-spray were applied as standalone systems to the one-room building. The theoretical simulation calculations were performed for typical summer weather conditions of Stellenbosch, South Africa. Under base case conditions and for a room thermostat setting of 22 ºC the peak cooling load of the one-room building was 74.73 W/m². With the application of night flushing between the hours of 24:00 and 07:00, the room cooling load was reduced by 5.2% by providing 3.9 W/m² of cooling and reducing the peak room temperature by 1.4 ºC. The active mass cooling system was modelled by supplying water at a constant supply temperature of 15 ºC to a pipe network embedded in the roof slab of the one-room building. The sea may typically be considered as a cold water source for buildings situated at the coast. The active mass cooling system reduced the peak cooling load of the one-room building by 50% by providing 37.2 W/m² of cooling and reducing the peak room temperature by 6.7 ºC. When the roof-spray and roof-pond systems were applied as standalone systems to the oneroom building, the peak cooling load of the one-room building could be reduced by 30% and 51% respectively. This is equivalent to 22.3 W/m² of peak cooling by the roof-spray and 38 W/m² of peak cooling by the roof-pond. The roof-spray reduced the peak room temperature by 3.71 ºC while the roof-pond reduced the peak room temperature by 5.9 ºC. Applying the roof cooling system to the one-room building produced 46 W/m² of peak cooling which resulted in a 61.1% reduction in peak cooling load. The roof cooling system reduced the peak temperature by 8 ºC. By comparing the sustainable cooling alternatives, the roof cooling system showed to be the most effective in reducing the one-room building peak cooling load. Over a 24 hour period the roof cooling system reduced the net heat entry to the one-room building by 57.3%. In a further attempt to reduce the peak cooling load, the sustainable cooling alternatives were applied in combinations to the one-room building. The combination of night flushing and roof-spray reduced the peak cooling load by 36% while a combination of night flushing and active mass cooling reduced the peak cooling load by 55%. Combining night flushing with the roof-pond also yielded a 55% peak cooling load reduction. The combination of roofpond, active mass cooling and night flushing provided 51 W/m² of cooling which corresponded to a 68% reduction in peak cooling load. Utilising the sustainable cooling alternatives in a combination in the one-room building gave improved results when compared to the case where the sustainable cooling alternatives were employed as standalone systems. It is illustrated by means of a sensitivity analysis that the ability of the roof cooling system to produce cool water is largely influenced by ambient conditions, droplet diameter and roofspray rate. Under clear sky conditions, an ambient temperature of 15 ºC, relative humidity of 80%, a roof-spray rate of 0.02 kg/sm² and a roof-pond water level of 100mm, water could be cooled at a rate of 113 W/m². The roof-spray energy contributed to 28 W/m² whilst the night sky radiation was responsible for 85 W/m² of the water cooling. It must however be noted that the water of the roof cooling system can never be reduced to a temperature that is lower than the ambient dew point temperature. / AFRIKAANSE OPSOMMING: Die tesis is geïnisieer deur ‘n Raadgewende Ingenieurs Maatskappy (KV3) as a navorsingsprojek om verskeie opsies te ondersoek waarmee die effektiwiteit en energie verbruik van konvensionele lugversorgingstelsels verbeter kan word deur middel van alternatiewe en hernubare energie. Agt opsies is oorspronglik geïdentifiseer en deur middel van ‘n proses waarby die graad van kommersialisering van hierdie alternatiewe maniere bepaal is, kon die opsies verminder word tot drie. Hierdie opsies, ook verwys na as die volhoubare verkoelingsalternatiewe, sluit in aktiewe massa verkoeling, dakverkoeling en nagventilasie. Die dakverkoelingstelsel bestaan uit dakwater, ‘n dakspuit, ‘n pomp en ‘n stoortenk. Die dakverkoelingstelsel is wiskundig en eksperimenteel gemodelleer. Die dakverkoelingseksperiment is uitgevoer onder ‘n verskeidenheid van weersomstandighede. Die dakwater asook die stoortenk se water temperatuur is voortdurend aangeteken. Dieselfde weer- en insetkondisies is gebruik vir die simulasie berekening en die temperature van die stoortenk se water en die dakwater is vergelyk met die temperatuurlesings van die eksperimentele werk. Die temperature van die eksperimentele lesings het goed vergelyk met die temperatuur simulasie berekeninge. Die grootste verskil tussen die simulasie en eksperimentele temperatuur was in die orde grootte van 1 ºC. ‘n Een-kamer gebou is aangeneem om as basis te dien waarop die volhoubare verkoelingsalternatiewe aangewend kon word vir teoretiese simulasie. Die een-kamer gebou het uit vier buite mure en ‘n horisontale beton dak bestaan. Nag ventilasie, aktiewe massa verkoeling en die dakverkoelingstelsel is toegepas op die een-kamer gebou en die kamer se verkoelingslas asook die kamer se lugtempertuur is teoreties gesimuleer. Die teoretiese simulasies is ook herhaal vir die geval waar die dakwater and dakspuitstelsel apart aangewend is op die een-kamer gebou. Die teoretiese simulasie berekeninge is uitgevoer vir tipiese somer weersomstandighede vir Stellenbosch, Suid Afrika. Onder basisgeval omstandighede, waar die een-kamer gebou gesimuleer is, sonder enige volhoubare verkoelingsalternatiewe en ‘n termostaat verstelling van 22 ºC, is die piek verkoelingslas bereken as 74.73 W/m². Met die toepassing van nagventilasie tussen die ure 24:00 en 07:00 was die piekverkoelingslas van die kamer verminder met 5.2% deur 3.9 W/m² se verkoeling te verskaf en die piekkamer temperatuur te verminder met 1.4 ºC. Aktiewe massa verkoeling is gesimuleer deur water teen ‘n konstante temperatuur van 15 ºC te verskaf aan ‘n pypnetwerk, geïnstalleer in the beton dak, van die een-kamer gebou. Geboue geleë aan die kus kan tipies seewater oorweeg as ‘n bron van koue water. Aktiewe massa verkoeling het die piekverkoelingslas van die een-kamer gebou verminder met 50% deur 37.2 W/m² se verkoeling te verskaf en die piekkamer temperatuur te verminder met 6.7 ºC. Wanneer die dakspuit- en dakwaterstelsel aangewend is op die een-kamer gebou as enkel staande stelsels, is die piekverkoelingslas verminder met 30% en 51% onderskeidelik. Dit is ekwivalent aan 22.3 W/m² se verkoeling vir die dakspuitstelsel en 38 W/m² se verkoeling vir die dakwaterstelsel. Die dakspuitstelsel het die piekkamer temperatuur verminder met 3.71 ºC terwyl die dakwaterstelsel ‘n 5.9 ºC verlaging in piekkamer temperatuur tot gevolg gehad het. Die dakverkoelingstelsel het 46 W/m² se piekverkoeling verskaf wat ‘n 61.1% vermindering in piekverkoelingslas tot gevolg gehad het. Die ooreenstemmende piek temperatuur vermindering is 8 ºC. Deur die verskeie volhoubare verkoelingsalternatiewe met mekaar te vergelyk, word getoon dat die dakverkoelingstelsel die mees effektiefste manier is om die een- kamer se piekverkoelingslas te verminder. Oor ‘n tydperk van 24 uur het die dakverkoelingstelsel die totale energievloei na die een-kamer gebou met 57.3% verminder. In ‘n verdere poging om die piekverkoelingslas te verminder, is die volhoubare verkoelingsalternatiewe toegepas in kombinasies op die een-kamer gebou. Die kombinasie van nagventilasie met die dakspuitstelsel het die piekverkoelingslas met 36% verminder, terwyl ‘n kombinasie van nagventilasie en aktiewe massa verkoeling ‘n 55% vermindering in piekverkoelingslas tot gevolg gehad het. Die kombinasie van dakwater en nagventilasie het ook ‘n piekverkoelingslas vermindering van 55% teweeggebring. Die kombinasie van dakwater, aktiewe massa verkoeling en nagventilasie het 51 W/m² se verkoeling veskaf, wat ooreenstem met ‘n 68% vermindering in piekverkoelingslas. Deur die volhoubare verkoelingsalternatiewe in kombinasies toe te pas op die een-kamer gebou, kon beter resultate verkry word toe dit vergelyk is met die geval waar die volhoubare verkoelingsalternatiewe as enkelstaande stelsels toegepas is. Dit is geïllustreer deur middel van ‘n sensitiwiteitsanalise dat die vermoë van die dakverkoelingstelsel om koue water te produseer, beïnvloed word deur buitelug kondisies, waterdruppel deursnee en dakspuit massa vloeitempo. Onder die oop hemelruimteomstandighede, ‘n buitelug temperatuur van 15 ºC, ‘n relatiewe humiditeit van 80%, ‘n dakspuit massa vloeitempo van 0.02 kg/sm² en dakwatervlak van 100 mm, kon water verkoel word teen ‘n tempo van 113 W/m². Die dakspuit gedeelte het 28 W/m² bygedra terwyl die nagruim radiasie sowat 85 W/m² se verkoeling verskaf het. Daar moet egter kennis geneem word dat die water temperatuur van die dakverkoelingstelsel nooit verminder kan word tot onder die buitelug doupunttemperatuur nie.
73

School campus @ Tsui Ping Estate. / School campus at Tsui Ping Estate

January 2002 (has links)
Lau Yiu Wing Terry. / "Architecture Department, Chinese University of Hong Kong, Master of Architecture Programme 2001-2002, design report." / Includes bibliographical references (leaves 74). / Chapter 1.0 --- INTRODUCTION / Chapter 1.01 --- synopsis / Chapter 1.02 --- background information / Chapter 1.03 --- "what, why,...." / Chapter 3.0 --- CASE STUDIES / Chapter 3.00 --- Research and study / Chapter 3.01 --- Living Pattern / Chapter 3.02 --- Case studies in standard schools / Chapter 3.03 --- School in Shanghai / Chapter 3.04 --- International School in Shanghai / Chapter 3.05 --- School in Japan / Chapter 3.06 --- International School in Hong Kong / Chapter 3.07 --- Local School in Hong Kong / Chapter 3.08 --- School Village / Chapter 3.09 --- "Pros of the idea of ""School Village""" / Chapter 5.0 --- SITE INVESTIGATION / Chapter 5.01 --- Site Analysis Diagrams / Chapter 5.02 --- Air Pollution / Chapter 5.03 --- Population Diagrams / Chapter 5.04 --- Accessibility and Traffic Flow Diagrams / Chapter 5.05 --- Existing Facilities information / Chapter 5.06 --- Existing School Information / Chapter 5.07 --- Conclusion / Chapter 7.0 --- DESIGN AND DEVELOPMENT / Chapter 7.01 --- Study Model scheme / Chapter 7.02 --- Site Model Design / Chapter 7.03 --- Final Model Design / Chapter 7.04 --- Design diagrams / Chapter 7.05 --- Architectural consideration / Chapter 7.06 --- Scheme design / Chapter 7.07 --- "Special Study- Bridge Detail, Building Service and Interior" / Chapter 9.0 --- RECORDS INFORMATION / Chapter 9.01 --- Interview / Chapter 9.02 --- Bibliography / Chapter 9.03 --- Presentation Records / Chapter 2.0 --- HYPOTHESIS / Chapter 2.01 --- Purpose of thesis / Chapter 2.02 --- The ideal school environment - A School Village / Chapter 4.0 --- SITE SELECTION / Chapter 4.01 --- Option One 一 Kowloon Tong / Chapter 4.02 --- Option Two 一 Boma Hill / Chapter 4.03 --- Option Three 一 Kwun Tong / Chapter 6.0 --- DESIGN ELEMENTS / Chapter 6.01 --- Land use / Chapter 6.02 --- Planning precepts / Chapter 6.03 --- Design for integration / Chapter 6.04 --- Design strategy / Chapter 6.05 --- Social distance / Chapter 6.06 --- Design program / Chapter 6.07 --- Newspaper cutting / Chapter 8.0 --- PRECEDENT STUDIES AND APPENDIX / Chapter 8.01 --- Bernard Tschumi 一 Pare de la Villette / Chapter 8.02 --- Christian Norberg-Schulz Intentions in Architecture
74

School construction: meeting the classroom building needs of Florida's growing student population

Unknown Date (has links)
Schools must have adequate classroom space available in order to educate the growing population of school age students in Florida. School concurrency is one method used to attempt to have seats available in schools as the need arises. Two Florida counties that have attempted to implement school concurrency are presented in a case study format as well as a Nevada county that has taken a different approach to managing the same issue. Through an analysis of documents, interviews and district data, a hypothesized model is tested and modified to present one method of providing adequate classroom space in Florida schools. / by Tracey Miller. / Thesis (Ed.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.
75

The optimum outrigger locations in outrigger-braced structures with new governing equations and complex objectives

Wang, Xing Hua January 2010 (has links)
University of Macau / Faculty of Science and Technology / Department of Civil and Environmental Engineering
76

Measuring sustainability perceptions of construction materials

Florez, Laura 24 May 2010 (has links)
As more owners seek to develop sustainable buildings, the construction industry is adapting to new requirements in order to meet owner's concerns. Material selection has been identified as an area where designers and contractors can have a significant impact on the sustainable performance of a building. Objective factors such as design considerations and cost constraints can play a role in the selection of materials. However, there may be subjective factors that could also impact the selection of materials. Building upon the potential impact of sustainability perceptions in an optimization model that can be used to help decision makers to select materials, this study defines and tests an instrument to identify and measure such perceptions. The purpose of this dissertation is to develop a conceptual instrument that measures the user-based assessment of product sustainability and validates decision-maker's perceptions in order to evaluate the contribution of subjective characteristics in materials selection. A survey of design and construction students and practitioners is carried out to capture the subjective factors included in the instrument. A Factor Analysis approach is used to refine and validate the measurement instrument and predict decision-makers' sustainability appraisal due to the factors considered.
77

Directed visibility analysis: three case studies on the relationship between building layout, perception and behavior

Lu, Yi 01 April 2011 (has links)
This is a study of the spatial affordances of buildings that allow them to organize and transmit cultural ideas and to support the performance of organizational roles. The particular affordances under consideration are those that arise from the manner in which buildings structure the visual fields that are potentially available to a situated observer. In studying directed visibility patterns, supported by the development of appropriate analytical tools, we focus on a previously specified set of visual targets and ask how many become visible from each occupiable location. Parametric restrictions concerning the direction into which a subject faces and the viewing angle sustained by the target object are also taken into consideration. The aim is to demonstrate how such refinements of visibility analysis, lead to more precise and penetrating insights as to how building users tune their behavior to the spatial affordances of environment, and how the environment impacts their understanding in turn. Three different studies were presented. The fist used directed visibility measures to evaluate the affordances of different nursing-unit designs relative to how well nurses are able to survey patients in different rooms as they go about their duties. The second study focuses on the manner in which nurses and physicians position themselves in a Neuro Intensive Care Unit (ICU), particularly when interacting. The third study investigates how aware exhibition visitors become of the visual structure of environment and how the visibility structure of exhibitions affects the ability of visitors to conceptually group paintings according to their thematic content. The case studies support the following conclusions. 1) The way in which people position themselves in an environment as they perform their assigned tasks is tuned to the way in which visual fields are structured. 2) The visual structure of environment is contingent upon the interaction between the underlying structure of visual fields and paths of movement. 3) Directed visibility analysis leads to stronger correlations with behavior and performance than generic visibility analysis. This implies that environments are layered. Their underlying spatial structure is charged by the distribution of the contents that are programmatically primary.
78

Kartläggning av Stockholms, Göteborgs och Malmös hantering av miljonprogramsområden : ur kommunernas och de kommunala bostadsbolagens perspektiv / Mapping of Stockholm, Gothenburg and Malmo's handling of the million programme areas

Back, Cornelia, Gustafsson, Julia January 2015 (has links)
Miljonprogrammet är namnet på det politiska projektet som pågick mellan åren 1965 och 1974 då riksdagen fattat ett beslut om att en miljon nya bostäder skulle byggas i Sverige, för att råda bot på bostadsbristen. Nu är det mer än 40 år sedan byggnaderna uppfördes och renoveringsbehovet är ett faktum, vilket gör ämnet aktuellt. Huvudsyftet med studien är att kartlägga de tre största städernas hantering av renoveringsbehovet. Huvudfrågan för studien är hur miljonprogrammets bostäder hanteras idag. Samtidigt har en rad andra frågor besvarats i studien; vilka skillnader som finns i lagarna då och nu, hur miljonprogramsområdena ser ut i de olika städerna och hur de behandlas i översiktsplanerna, vilka följder som uppstår av att husen behöver renoveras samt om det finns någon ekonomi i att renovera husen.Studien har genomförts med en kombination av kvalitativ och kvantitativ metod. En kvalitativ genomgång av skrivet material med anknytning till miljonprogrammet i de tre städerna har gjorts. Därutöver har också en kvantitativ enkätundersökning skickats ut till de tre kommunerna och dess kommunala bostadsbolag.Stockholm, Göteborg och Malmö har både likheter och skillnader gällande planering och visioner. Både Stockholm och Göteborg har valt att placera sina miljonprogramsområden utanför stadskärnan medan Malmös ligger i nära anslutning till centrum. De har alla visioner i sina översiktsplaner om att skapa en mer enhetlig och sammankopplad stad genom ökad integration och bättre kommunikationer mellan stadens olika delar.Det uppstod en renoveringsvåg under 80- och 90-talet i samband med ROT-avdraget och idag pågår flera projekt kring miljonprogrammet. Fasadrenovering är vanligt i alla tre städerna och även till viss del upprustning av balkonger och fönster. Göteborg har satsat mycket på energieffektiviserande åtgärder och i Stockholm har det blivit allt vanligare med energi-besparade ingrepp såsom tilläggsisolering.Lagstiftningen i Sverige har stor betydelse vid renoveringen då det idag finns krav på bl.a. energieffektivitet men även under renoveringsvågen på 80- och 90-talet då varsamhetskravet infördes i PBL 1987. Stommen i bostäderna är bra och de är funktionellt byggda vilket gör att renovering är mer kostnadseffektivt än att riva och bygga nytt. Problemet ligger alltså inte i renoveringsbehovet, då de flesta hus behöver renoveras efter så pass många år, utan antalet hus som behöver renoveras. / The million programme is a building era that took place between the years 1965 to 1974 when a politic decision was made to build a million new residences in Sweden, to correct the housing shortage. It´s now been more than 40 years since these residences were built and the need to renovate is a necessity, which makes this programme a very current subject. The purpose of this study is to map the three largest city´s handling of the need for renovation. The main question of this study is how the buildings of the million programme is being handled today. Meanwhile a series of other questions have been answered in this study; the difference between laws now and then, how the million programme areas looks in the different cities and how they are treated in the layout plans, what the need for renovation might lead to, and if there is any profit in restoring the buildings.It is a qualitative study as it is a situation in a few cities that are being studied, but through a survey this study gets a quantitative mixture as well. A survey was dispatched to the three municipalities and their communal real estate companies.Malmo, Gothenburg and Stockholm are both similar and different regarding planning and visions. Both Gothenburg and Stockholm placed their million programmes outside of the city´s core, whilst Malmo´s was located close to the centre of the city. They all have visions in their layout plans to create a more unified and connected city through increased integration and better communication between the city areas.There was a wave of renovation in the eighties and nineties because of the ROT-deduction and many projects concerning the million programme are still ongoing to this day. Facade renovation is common in all three cities and, to a certain degree, restoration of balconies and windows. Gothenburg has invested a lot in energy efficient measures and in Stockholm it has become increasingly more common with energy saving interventions like adding increased isolation. The image of the million programme´s constructions is "concrete ghettos", but the most common houses consists of three storeys with apartment size 3 rok.The Swedish legislation are of great importance during the renovation as there now are requirements on energy efficiency amongst other things, but also during the wave of renovation in the eighties and nineties when the demand of discretion was enforced in PBL 1987. The foundation in the million programme houses is satisfactory and they are functionally built which makes a renovation more cost-efficient than it would be to tear it down and build new buildings. The problem then does not reside in the need for renovation, as most houses needs restoration after so many years, but in the sheer number of buildings that would require a renovation.
79

Sports theme park: redevelopment of South China Athletic Association

王駿傑, Wong, Chun-kit, Alex. January 2000 (has links)
published_or_final_version / Architecture / Master / Master of Architecture
80

Property management strategies and real estate design: a case study of Hong Kong

Yuen, Ying-lai, Margaret., 袁映麗. January 1995 (has links)
published_or_final_version / Housing Management / Master / Master of Housing Management

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