24 resultados para Hydrologic sciences|Civil engineering|Environmental engineering
em CentAUR: Central Archive University of Reading - UK
Resumo:
The collection of wind speed time series by means of digital data loggers occurs in many domains, including civil engineering, environmental sciences and wind turbine technology. Since averaging intervals are often significantly larger than typical system time scales, the information lost has to be recovered in order to reconstruct the true dynamics of the system. In the present work we present a simple algorithm capable of generating a real-time wind speed time series from data logger records containing the average, maximum, and minimum values of the wind speed in a fixed interval, as well as the standard deviation. The signal is generated from a generalized random Fourier series. The spectrum can be matched to any desired theoretical or measured frequency distribution. Extreme values are specified through a postprocessing step based on the concept of constrained simulation. Applications of the algorithm to 10-min wind speed records logged at a test site at 60 m height above the ground show that the recorded 10-min values can be reproduced by the simulated time series to a high degree of accuracy.
Resumo:
The United Nation Intergovernmental Panel on Climate Change (IPCC) makes it clear that climate change is due to human activities and it recognises buildings as a distinct sector among the seven analysed in its 2007 Fourth Assessment Report. Global concerns have escalated regarding carbon emissions and sustainability in the built environment. The built environment is a human-made setting to accommodate human activities, including building and transport, which covers an interdisciplinary field addressing design, construction, operation and management. Specifically, Sustainable Buildings are expected to achieve high performance throughout the life-cycle of siting, design, construction, operation, maintenance and demolition, in the following areas: • energy and resource efficiency; • cost effectiveness; • minimisation of emissions that negatively impact global warming, indoor air quality and acid rain; • minimisation of waste discharges; and • maximisation of fulfilling the requirements of occupants’ health and wellbeing. Professionals in the built environment sector, for example, urban planners, architects, building scientists, engineers, facilities managers, performance assessors and policy makers, will play a significant role in delivering a sustainable built environment. Delivering a sustainable built environment needs an integrated approach and so it is essential for built environment professionals to have interdisciplinary knowledge in building design and management . Building and urban designers need to have a good understanding of the planning, design and management of the buildings in terms of low carbon and energy efficiency. There are a limited number of traditional engineers who know how to design environmental systems (services engineer) in great detail. Yet there is a very large market for technologists with multi-disciplinary skills who are able to identify the need for, envision and manage the deployment of a wide range of sustainable technologies, both passive (architectural) and active (engineering system),, and select the appropriate approach. Employers seek applicants with skills in analysis, decision-making/assessment, computer simulation and project implementation. An integrated approach is expected in practice, which encourages built environment professionals to think ‘out of the box’ and learn to analyse real problems using the most relevant approach, irrespective of discipline. The Design and Management of Sustainable Built Environment book aims to produce readers able to apply fundamental scientific research to solve real-world problems in the general area of sustainability in the built environment. The book contains twenty chapters covering climate change and sustainability, urban design and assessment (planning, travel systems, urban environment), urban management (drainage and waste), buildings (indoor environment, architectural design and renewable energy), simulation techniques (energy and airflow), management (end-user behaviour, facilities and information), assessment (materials and tools), procurement, and cases studies ( BRE Science Park). Chapters one and two present general global issues of climate change and sustainability in the built environment. Chapter one illustrates that applying the concepts of sustainability to the urban environment (buildings, infrastructure, transport) raises some key issues for tackling climate change, resource depletion and energy supply. Buildings, and the way we operate them, play a vital role in tackling global greenhouse gas emissions. Holistic thinking and an integrated approach in delivering a sustainable built environment is highlighted. Chapter two demonstrates the important role that buildings (their services and appliances) and building energy policies play in this area. Substantial investment is required to implement such policies, much of which will earn a good return. Chapters three and four discuss urban planning and transport. Chapter three stresses the importance of using modelling techniques at the early stage for strategic master-planning of a new development and a retrofit programme. A general framework for sustainable urban-scale master planning is introduced. This chapter also addressed the needs for the development of a more holistic and pragmatic view of how the built environment performs, , in order to produce tools to help design for a higher level of sustainability and, in particular, how people plan, design and use it. Chapter four discusses microcirculation, which is an emerging and challenging area which relates to changing travel behaviour in the quest for urban sustainability. The chapter outlines the main drivers for travel behaviour and choices, the workings of the transport system and its interaction with urban land use. It also covers the new approach to managing urban traffic to maximise economic, social and environmental benefits. Chapters five and six present topics related to urban microclimates including thermal and acoustic issues. Chapter five discusses urban microclimates and urban heat island, as well as the interrelationship of urban design (urban forms and textures) with energy consumption and urban thermal comfort. It introduces models that can be used to analyse microclimates for a careful and considered approach for planning sustainable cities. Chapter six discusses urban acoustics, focusing on urban noise evaluation and mitigation. Various prediction and simulation methods for sound propagation in micro-scale urban areas, as well as techniques for large scale urban noise-mapping, are presented. Chapters seven and eight discuss urban drainage and waste management. The growing demand for housing and commercial developments in the 21st century, as well as the environmental pressure caused by climate change, has increased the focus on sustainable urban drainage systems (SUDS). Chapter seven discusses the SUDS concept which is an integrated approach to surface water management. It takes into consideration quality, quantity and amenity aspects to provide a more pleasant habitat for people as well as increasing the biodiversity value of the local environment. Chapter eight discusses the main issues in urban waste management. It points out that population increases, land use pressures, technical and socio-economic influences have become inextricably interwoven and how ensuring a safe means of dealing with humanity’s waste becomes more challenging. Sustainable building design needs to consider healthy indoor environments, minimising energy for heating, cooling and lighting, and maximising the utilisation of renewable energy. Chapter nine considers how people respond to the physical environment and how that is used in the design of indoor environments. It considers environmental components such as thermal, acoustic, visual, air quality and vibration and their interaction and integration. Chapter ten introduces the concept of passive building design and its relevant strategies, including passive solar heating, shading, natural ventilation, daylighting and thermal mass, in order to minimise heating and cooling load as well as energy consumption for artificial lighting. Chapter eleven discusses the growing importance of integrating Renewable Energy Technologies (RETs) into buildings, the range of technologies currently available and what to consider during technology selection processes in order to minimise carbon emissions from burning fossil fuels. The chapter draws to a close by highlighting the issues concerning system design and the need for careful integration and management of RETs once installed; and for home owners and operators to understand the characteristics of the technology in their building. Computer simulation tools play a significant role in sustainable building design because, as the modern built environment design (building and systems) becomes more complex, it requires tools to assist in the design process. Chapter twelve gives an overview of the primary benefits and users of simulation programs, the role of simulation in the construction process and examines the validity and interpretation of simulation results. Chapter thirteen particularly focuses on the Computational Fluid Dynamics (CFD) simulation method used for optimisation and performance assessment of technologies and solutions for sustainable building design and its application through a series of cases studies. People and building performance are intimately linked. A better understanding of occupants’ interaction with the indoor environment is essential to building energy and facilities management. Chapter fourteen focuses on the issue of occupant behaviour; principally, its impact, and the influence of building performance on them. Chapter fifteen explores the discipline of facilities management and the contribution that this emerging profession makes to securing sustainable building performance. The chapter highlights a much greater diversity of opportunities in sustainable building design that extends well into the operational life. Chapter sixteen reviews the concepts of modelling information flows and the use of Building Information Modelling (BIM), describing these techniques and how these aspects of information management can help drive sustainability. An explanation is offered concerning why information management is the key to ‘life-cycle’ thinking in sustainable building and construction. Measurement of building performance and sustainability is a key issue in delivering a sustainable built environment. Chapter seventeen identifies the means by which construction materials can be evaluated with respect to their sustainability. It identifies the key issues that impact the sustainability of construction materials and the methodologies commonly used to assess them. Chapter eighteen focuses on the topics of green building assessment, green building materials, sustainable construction and operation. Commonly-used assessment tools such as BRE Environmental Assessment Method (BREEAM), Leadership in Energy and Environmental Design ( LEED) and others are introduced. Chapter nineteen discusses sustainable procurement which is one of the areas to have naturally emerged from the overall sustainable development agenda. It aims to ensure that current use of resources does not compromise the ability of future generations to meet their own needs. Chapter twenty is a best-practice exemplar - the BRE Innovation Park which features a number of demonstration buildings that have been built to the UK Government’s Code for Sustainable Homes. It showcases the very latest innovative methods of construction, and cutting edge technology for sustainable buildings. In summary, Design and Management of Sustainable Built Environment book is the result of co-operation and dedication of individual chapter authors. We hope readers benefit from gaining a broad interdisciplinary knowledge of design and management in the built environment in the context of sustainability. We believe that the knowledge and insights of our academics and professional colleagues from different institutions and disciplines illuminate a way of delivering sustainable built environment through holistic integrated design and management approaches. Last, but not least, I would like to take this opportunity to thank all the chapter authors for their contribution. I would like to thank David Lim for his assistance in the editorial work and proofreading.
Resumo:
Concern for the environmental impact of organizations’ activities has led to the recognition and demand for organizations to manage and report on their carbon footprint. However, there is no limit as to the areas of carbon footprints required in such annual environmental reports. To deliver improvements in the quality of carbon footprint management and reporting, there is a need to identify the main elements of carbon footprint strategy that can be endorsed, supported and encouraged by facility managers. The study investigates carbon footprint elements managed and reported upon by facility manager in the UK. Drawing on a questionnaire survey of 256 facility managers in the UK, the key elements of carbon footprints identified in carbon footprint reports are examined. The findings indicate that the main elements are building energy consumption, waste disposal and water consumption. Business travel in terms of using public transport, air travel and company cars are also recognized as important targets and objectives for the carbon footprint strategy of several FM (facilities management) organizations.
Resumo:
This book is aimed primarily at students for whom the study of building or civil engineering contracts forms part of a construction-based course. We have had in mind the syllabus requirements for first degrees in Building, Civil Engineering, Architecture, Quantity Surveying and Building Surveying, as well as those of postgraduate courses in Construction Management and Project Management. We have also assumed that such students will already have been introduced to the general principles of English law, especially those relating to contract and tort. As a result, while aspects of those subjects that are of particular relevance to construction are dealt with here, the reader must look elsewhere for the general legal background. In producing this third edition, we have again been greatly assisted by the many helpful comments made by reviewers and users of its predecessor. Nonetheless, our basic aim is identical to that which underpinned the first edition: to provide an explanation of the fundamental principles of construction contract law, rather than a clause-by-clause analysis of any particular standard-form contract. As a result, while we draw most frequently upon JCT 98 for our illustrations of particular points, this merely reflects the pre-eminent position occupied by that particular form of contract in the UK construction industry. We conclude by repeating our previous warning as to the dangers inherent in a little learning. Neither this book, nor the courses for which it is intended, seek to produce construction lawyers. The objective is rather to enable those who are not lawyers to resolve simple construction disputes before they become litigious, and to recognize when matters require professional legal advice. It should be the aim of every construction student to understand the legal framework sufficiently that they can instruct and brief specialist lawyers, and this book is designed to help them towards that understanding.
Resumo:
Purpose – For many academics in UK universities the nature and orientation of their research is overwhelmingly determined by considerations of how that work will be graded in research assessment exercises (RAEs). The grades awarded to work in a particular subject area can have a considerable impact on the individual and their university. There is a need to better understand those factors which may influence these grades. The paper seeks to address this issue. Design/methodology/approach – The paper considers relationships between the grades awarded and the quantitative information provided to the assessment panels for the 1996 and 2001 RAEs for two subject areas, built environment and town and country planning, and for three other subject areas, civil engineering, geography and archaeology, in the 2001 RAE. Findings – A simple model demonstrating strong and consistent relationships is established. RAE performance relates to numbers of research active staff, the production of books and journal papers, numbers of research studentships and graduations, and research income. Important differences between subject areas are identified. Research limitations/implications – Important issues are raised about the extent to which the new assessment methodology to be adopted for the 2008 RAE will capture the essence of good quality research in architecture and built environment. Originality/value – The findings provide a developmental perspective of RAEs and show how, despite a changed methodology, various research activities might be valued in the 2008 RAE. The basis for a methodology for reviewing the credibility of the judgements of panels is proposed.
Resumo:
In the tender process, contractors often rely on subcontract and supply enquiries to calculate their bid prices. However, this integral part of the bidding process is not empirically articulated in the literature. Over 30 published materials on the tendering process of contractors that talk about enquiries were reviewed and found to be based mainly on experiential knowledge rather than systematic evidence. The empirical research here helps to describe the process of enquiries precisely, improve it in practice, and have some basis to support it in theory. Using a live participant observation case study approach, the whole tender process was shadowed in the offices of two of the top 20 UK civil engineering construction firms. This helped to investigate 15 research questions on how contractors enquire and obtain prices from subcontractors and suppliers. Forty-three subcontract enquiries and 18 supply enquiries were made across two different projects with average value of 7m. An average of 15 subcontract packages and seven supply packages was involved. Thus, two or three subcontractors or suppliers were invited to bid in each package. All enquiries were formulated by the estimator, with occasional involvement of three other personnel. Most subcontract prices were received in an average of 14 working days; and supply prices took five days. The findings show 10 main activities involved in processing enquiries and their durations, as well as wasteful practices associated with enquiries. Contractors should limit their enquiry invitations to a maximum of three per package, and optimize the waiting time for quotations in order to improve cost efficiency.
Resumo:
The main aim of this study was to ascertain and discuss the current challenges and opportunities facing construction contractors in Ghana. This involved a review of the economic, legal and political environments in which contractors in Ghana operate; a review of published studies on construction in developing countries generally and Ghana specifically; and in-depth interviews and discussions with seven building and civil engineering contractors in Ghana in 2009 and 2010. Six road contractors were also interviewed. The findings indicate significant challenges relating mainly to financing for projects and a harsh business environment. However, most contractors interviewed admitted to significant problems in their own organisations. It is clear that the contracting environment in Ghana is harsh particularly for local contractors who are often not paid on time and without compensation for late payment. However, local construction firms in Ghana who want to breakthrough ought to formulate the right strategic plans, develop innovative business strategies, develop professionalism, and merge with local firms with similar organisational values and characteristics. In short, local or indigenous Ghanaian contractors ought to face up to the reality of competition and the dynamics of modern business in order to survive, grow and become major players in the construction industry in Ghana.
Resumo:
The method of entropy has been useful in evaluating inconsistency on human judgments. This paper illustrates an entropy-based decision support system called e-FDSS to the solution of multicriterion risk and decision analysis in projects of construction small and medium enterprises (SMEs). It is optimized and solved by fuzzy logic, entropy, and genetic algorithms. A case study demonstrated the use of entropy in e-FDSS on analyzing multiple risk criteria in the predevelopment stage of SME projects. Survey data studying the degree of impact of selected project risk criteria on different projects were input into the system in order to evaluate the preidentified project risks in an impartial environment. Without taking into account the amount of uncertainty embedded in the evaluation process; the results showed that all decision vectors are indeed full of bias and the deviations of decisions are finally quantified providing a more objective decision and risk assessment profile to the stakeholders of projects in order to search and screen the most profitable projects.
Resumo:
The paper provides details of the size and scope of construction research carried out in a number of architecture, civil engineering and building related departments in British universities. After considering the level of funding, the type of research projects undertaken and the resulting outputs, especially how these benefit industry, the paper focuses on the careers of academics and researchers and the way in which research is organized at university, departmental and team levels. Finally, the paper suggests that whilst the construction research community in universities has many strengths, there is a danger that in responding to recent opportunities it may overreach itself. The end result may be disappointing for all parties involved. Some of the factors which would contribute to an effective approach to the development of links between universities and industry are discussed.
Resumo:
Built environment programmes in West African universities; and research contributions from West Africa in six leading international journals and proceedings of the WABER conference are explored. At least 20 universities in the region offer degree programmes in Architecture (86% out of 23 universities); Building (57%); Civil Engineering (67%); Estate Management (52%); Quantity Surveying (52%); Surveying and Geoinformatics (55%); Urban and Regional Planning (67%). The lecturer-student ratio on programmes is around 1:25 compared to the 1:10 benchmark for excellence. Academics who teach on the programmes are clearly research active with some having published papers in leading international journals. There is, however, plenty of scope for improvement particularly at the highest international level. Out of more than 5000 papers published in six leading international peer-reviewed journals since each of them was established, only 23 of the papers have come from West Africa. The 23 papers are published by 28 academics based in 13 universities. Although some academics may publish their work in the plethora of journals that have proliferated in recent years, new generation researchers are encouraged to publish in more established journals. The analyses of 187 publications in the WABER conference proceedings revealed 18 research-active universities. Factors like quality of teaching, research and lecturer-student ratio, etc count in the ranking of universities. The findings lay bare some of the areas that should be addressed to improve the landscape of higher education in West Africa.
Resumo:
The construction industry has become a truly global network of interconnected stakeholders making demands which require the involvement of skilled workforces from all over the world. Construction Management Strategies sets the foundations for understanding and managing construction’s inherent complexity and uniqueness. It establishes clear definitions of commonly accepted terms like built environment, construction, civil engineering, etc. which are often given confusing and conflicting interpretations. It cuts through the plethora of overlapping role titles currently used in the construction sector that make it difficult to establish how projects are actually managed.