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1
Adu-Gyamfi, Kwame. "Civil Engineering". Ohio University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1141840448.
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Jreissati, Wadih J. (Wadih Joseph) 1980. "Counterterrorism civil engineering design". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/29555.
Testo completoAbstract (sommario):
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003.Includes bibliographical references (leaf 51).
Because of the increasing concern about terrorist attacks, engineers have shown a substantial interest in making buildings safer for people. In order to come up with the most adequate design, experts have to carefully define the level of risk on the new structure, since people don't want to live in bunker-like buildings. Then, a good understanding of explosive devices will be a major help to keep the damage localized, preventing the overall collapse of the structure which can cause a lot more deaths than the explosion itself. The first and most important parameter is to secure the building's perimeter by increasing the standoff distance or by using security devices such as gates or even bollards around the building; careful site planning is essential and it costs a loss less when accounted for early in the design phase. Also, a wise choice of construction materials will mitigate blast effects; windows, doors, HVAC and firefighting systems should be designed to save lives and to not cause more injuries! Finally, the major driver for a successful blast protection is designing redundancies to carry the additional loads imposed by an explosion; structural members will therefore work as mediators for alternate load paths in the case of damage of their neighboring members.
by Wadih J. Jreissati.
M.Eng.
3
Hackman, Ian. "Nanocomposites in civil engineering". Thesis, University of Surrey, 2007. http://epubs.surrey.ac.uk/844542/.
Testo completoAbstract (sommario):
Chemically treated layered silicates (clays) can be combined with normal polymer matrix materials to form a nanocomposite in which clay layers are distributed throughout the material. Previous researchers have shown that these high aspect ratio clays can alter the properties of a range of thermoplastic and thermosetting polymers by a number of mechanisms; improving mechanical and thermal properties and reducing permeability. This study involves the investigation of these novel materials to assess their potential applicability within the civil engineering industry and to assess in which areas and situations they might be used. Extensive research was conducted into the processing required for these materials to achieve sufficient organoclay exfoliation with a range of matrix materials. The subsequent nanocomposite materials were assessed using a range of characterisation techniques including XRD, TEM, SEM, OM, TGA, DSC and FTIR spectroscopy. Organoclay morphology was found to be highly dependent on the type of surfactant and curing agent used and resulted in a variety of different types of nanocomposite being formed. A variety of new manufacturing techniques were developed to generate void free and dimensionally consistent pure polymer and fibre composite specimens that allowed the frequently subtle property variations due to organoclay to be detected. A range of mechanical, thermal and durability properties were investigated to assess the differences that organoclay can generate when incorporated in the pure polymer and in a glass or carbon fibre composite. Mechanical testing of the pure polymer revealed small increases in tensile, flexural and compressive properties in glassy polymers; whereas in elastomeric polymers the properties can be improved by a factor of 3 due to the high relative properties of organoclay compared to the polymer. When incorporated in a fibre composite the organoclay offered little improvement when in a glass fibre composite but was able to increase the properties of a carbon fibre composite. It is thought that this increase does not occur due to increased mechanical properties of the polymer commensurate with the law of mixtures theory but due to changes in the fibre-matrix interphase. The permeability of nanocomposites when exposed to water was not improved, although the solvent permeability of some matrix materials was significantly reduced. Although a high degree of nanoscale exfoliation had been achieved, with highly separated clay platelets, the macroscale dispersion was not sufficient to result in reductions in Fickian water uptake via a tortuous path mechanism. Whereas, the reduction in solvent permeability was thought to arise from changes in the rate of polymer relaxations due to polymer chain mobility being constrained by organoclay and altering the rate of Case II uptake. The mechanical durability of pure polymer and glass fibre nanocomposites and the thermal durability of pure polymer nanocomposites were investigated. Little improvement was observed in the long-term durability properties of these materials after prolonged environmental conditioning as a result of organoclay. The influence that organoclay has on polymer chain constraint was investigated by DSC and DRS to assess which combinations of materials develop significant changes to the polymer network. It was found that the same nanocomposite formulations that resulted in reduced solvent uptake also resulted in increased thermal and reduced dielectric properties. Due to the requirement for high quality processing and the need to control cure cycle the implementation of nanocomposites would only be feasible within a premanufactured product and could not be used onsite with confidence until new and improved materials or processing methods are developed. Reductions in permeability would have to be improved to a level beyond that observed in this investigation and to a level witnessed in a only a few cases involving epoxy nanocomposites to warrant the additional expense of incorporating and processing organoclay It cannot currently be guaranteed that this level of permeability improvement would be established due to the limited number of cases in which this has been achieved. Therefore, the present state of the art does not allow sufficient improvements to be attained and the development of superior organoclays capable of becoming exfoliated with relative ease, or methods of processing that are proven to be highly effective, cost efficient, reproducible and rapid would be required before this technology could be applied to civil engineering materials. However, the future potential of nanocomposite materials remain significant and their application in civil engineering composites will offer significant advantages as the technology develops to allow economical processing and increased property advantages.
4
Garcés, Francisco. "Identification of civil engineering structures". Phd thesis, Université Paris-Est, 2008. http://tel.archives-ouvertes.fr/tel-00470540.
Testo completoAbstract (sommario):
This thesis presents three methods to estimate and locate damage in framed buildings, simply-supported beams and cantilever structures, based on experimental measurements of their fundamental vibration modes. Numerical simulations and experimental essays were performed to study the effectiveness of each method. A numerical simulation of a multi-storey framed building, a real bridge and a real chimney were carried out to study the effectiveness of the methodologies in identifying damage. The influence of measurement errors and noise in the modal data was studied in all cases. To validate the experimental effectiveness of the damage estimation methods, static and dynamics tests were performed on a framed model, a simply supported beam, and a cantilever beam in order to determine the linear behavior changes due to the increase of the level of damage. The structural identification algorithms during this thesis were based on the knowledge type of the stiffness matrix or flexibility matrix to reduce the number of modal shapes and required coordinates for the structural assessment. The methods are intended to develop tools to produce a fast response and support for future decision procedures regarding to structures widely used, by excluding experimental information, thereby allowing a cost reduction of extensive and specific testing
5
Edrees, Tarek. "Structural Identification of Civil Engineering Structures". Licentiate thesis, Luleå tekniska universitet, Byggkonstruktion och -produktion, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26719.
Testo completoAbstract (sommario):
The assumptions encountered during the analysis and design of civil engineering structures lead to a difference in the structural behavior between calculations based models and real structures. Moreover, the recent approach in civil engineering nowadays is to rely on the performance-based design approaches, which give more importance for durability, serviceability limit states, and maintenance.Structural identification (St-Id) approach was utilized to bridge the gap between the real structure and the model. The St-Id procedure can be utilized to evaluate the structures health, damage detection, and efficiency. Despite the enormous developments in parametric time-domain identification methods, their relative merits and performance as correlated to the vibrating structures are still incomplete due to the lack of comparative studies under various test conditions and the lack of extended applications and verification of these methods with real-life data.This licentiate thesis focuses on the applications of the parametric models and non-parametric models of the System Identification approach to assist in a better understanding of their potentials, while proposing a novel strategy by combining this approach with the utilization of the Singular Value Decomposition (SVD) and the Complex Mode Indicator Function (CMIF) curves based techniques in the damage detection of structures.In this work, the problems of identification of the vertical frequencies of the top storey in a multi-storey¸ building prefabricated from reinforced concrete in Stockholm, and the existence of damage and damage locations for a bench mark steel frame are investigated. Moreover, the non-parametric structural identification approach to investigate the amount of variations in the modal characteristics (frequency, damping, and modes shapes) for a railway steel bridge will be presented.Godkänd; 2014; 20141023 (taredr); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Tarek Edrees Saaed Ämne: Konstruktionsteknik/Structural Engineering Uppsats: Structural Identification of Civil Engineering Structures Examinator: Professor Jan-Erik Jonasson, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Forskare Andreas Andersson, Brobyggnad inklusive Stålbyggnad, Kungliga Tekniska Högskolan Tid: Torsdag den 20 november 2014 kl 10:00 Plats: F1031, Luleå tekniska universitet
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Alim, Seema. "Fuzzy expert systems in civil engineering". Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/7183.
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Gheshlaghi, Farshad. "Tomographic imaging in civil engineering infrastructure". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq21349.pdf.
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Empie, Laurel E. "Measuring and interpreting civil engineering vibrations". Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/21430.
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O'Mahony, Margaret Mary. "Recycling of materials in civil engineering". Thesis, University of Oxford, 1990. http://ora.ox.ac.uk/objects/uuid:25b3c922-4720-4424-a2c6-b19f00013148.
Testo completoAbstract (sommario):
Although Britain is relatively rich in natural aggregate reserves, planning approvals to develop new quarries are running at about half the rate of aggregate extraction. The use of secondary materials, such as recycled aggregate, might not create a major course of aggregate but if secondary material were used in less demanding situations, the quantity of natural aggregate required by the construction industry would be reduced. This dissertation reports mainly on laboratory tests conducted on crushed concrete and demolition debris to examine the potential use of these materials in new construction. Standard aggregate tests were conducted on the materials to check their compliance with the Specification for Highway Works (1986), particularly for use as aggregate in road sub-base layers. A more detailed examination of the aggregates was conducted with regard to CBR, shear strength and frost susceptibility where the influences of moisture content, density and particle packing on these properties were investigated. One part of the study involved examining the use of recycled aggregate as the coarse aggregate fraction in new concrete. An analysis of the shear strength data was conducted using the dilatancy index defined by Bolton (1986). From the frost susceptibility results, it was concluded that further work would be required in this area to determine the main factors which influence the frost heave of recycled aggregates. The recycled aggregate concrete compared well with the natural aggregate concrete and appeared to be of superior quality than that produced in other research. During the study, it became evident that the recycled aggregates could perform as well as limestone in most cases and therefore could be considered for many potential uses. Some recommendations are presented at the end of this dissertation for the development of a standard on recycled materials which would help to promote the use of recycled aggregates in the construction industry in Britain.
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Vann, A. M. "Intelligent monitoring of civil engineering systems". Thesis, University of Bristol, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238845.
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Musyafa, Albani. "Stakeholders' satisfaction with civil engineering graduates". Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/133.
Testo completoAbstract (sommario):
Engineering education is being viewed as a fundamental matter in modern industry because engineering education produces graduates that are very important to the continued development of industry. Because of its importance, the quality of the engineering education should be improved continuously. Basically, the quality of education can be divided into the quality of the process and the quality of the outcome. The process includes the quality of the teaching, learning and curriculum, and the quality of the outcome is the quality of the competencies possessed by graduates. While the quality of curriculum and learning have been discussed in many scientific reports, the quality of competence is rarely discussed. Therefore, a study on the quality of graduates’ competence will be useful to augment recent studies on the quality of engineering education.The objective of this study is to analyse data of graduate quality so that useful information is obtained to help engineering education providers put strategies in place to improve its quality. The information includes the models linking quality and satisfaction.Data for this study including competence of graduates, performance of graduates, satisfaction of stakeholders, and expectations of stakeholders were obtained by survey with the questionnaire sets developed based on established variables and indicators. The targeted respondents are industry personnel monitoring graduates in workplaces. For comparison, data from academicians and professionals also were collected. Because of the diverse nature of engineering disciplines, the survey is limited to Civil Engineering graduates completing their studies from universities in Australia in recent years.The collected data were analysed using statistical methods in levels of samples and population. The variables related to competencies have been ranked so that the weaknesses and strengths of the competencies can be understood. The variables related to the expectations of stakeholders are also ranked so that the competencies that should be prioritized in education are identified. The characteristics of stakeholders’ satisfaction is defined based on the performance of graduates. Reliable models linking graduates’ competence and the stakeholders’ satisfaction have been developed. These findings will be useful to improve the quality of engineering education especially in the division of Civil Engineering.
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Cappelletto, Elisa. "Characterization of material for civil engineering". Doctoral thesis, Università degli studi di Trento, 2014. https://hdl.handle.net/11572/367727.
Testo completoAbstract (sommario):
Materials are the heart of engineering, which can be defined as the creative and rational use of materials for practical purposes. Materials have had an essential role in the development of civil engineering: from the beginning of human evolution, man has used many different materials to build houses, bridges, roads and countless other structures to make his life easier. Ancient populations used the raw materials at their disposal, such as stone, clay and timber. Over the centuries, the search for new materials became increasingly important to respond to changing human needs, and men learned how to use clay to form artificial stones, cements and concretes, for instance. While hands-on familiarity rooted in tradition and crafting expertise initially drove these human activities, in modern times the need for a scientific understanding of materials prompted the birth of the material science discipline. Material science studies the composition, behavior and properties of materials to solve problems associated with their use. Engineering and material science work together to create functional, durable and beautiful structures.
Among the materials used in civil engineering constructions, wood and cement have had the most important role over the centuries and they are still the main components of our infrastructures.
Timber was used as a building material even by primitive man, and a few ancient temples, palaces and bridges built of wood can still be seen today. In the 20th century, although materials such as concrete had become competitive, wood retained its significant role in building. The main problem with the use of wood as a construction material concerns its possibly limited lifetime. Wood is characterized by a limited resistance to moisture and fire, the two elements responsible for the destruction of most wooden buildings in the past.
Cement, and consequently concrete, is the most often used material today. The term “cement†is now used to mean a modern binder, the so-called Portland cement, patented in England in 1824. Similar binding materials were already being used from very early on ancient Mesopotamia, Egypt, Greece and Rome. Modern cement formulations have changed a great deal and can be adapted to their intended use and the surrounding environment.
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Cappelletto, Elisa. "Characterization of material for civil engineering". Doctoral thesis, University of Trento, 2014. http://eprints-phd.biblio.unitn.it/1226/1/PhD_Thesis_Characterization_of_Materials_Elisa_Cappelletto_.pdf.
Testo completoAbstract (sommario):
Materials are the heart of engineering, which can be defined as the creative and rational use of materials for practical purposes. Materials have had an essential role in the development of civil engineering: from the beginning of human evolution, man has used many different materials to build houses, bridges, roads and countless other structures to make his life easier. Ancient populations used the raw materials at their disposal, such as stone, clay and timber. Over the centuries, the search for new materials became increasingly important to respond to changing human needs, and men learned how to use clay to form artificial stones, cements and concretes, for instance. While hands-on familiarity rooted in tradition and crafting expertise initially drove these human activities, in modern times the need for a scientific understanding of materials prompted the birth of the material science discipline. Material science studies the composition, behavior and properties of materials to solve problems associated with their use. Engineering and material science work together to create functional, durable and beautiful structures.
Among the materials used in civil engineering constructions, wood and cement have had the most important role over the centuries and they are still the main components of our infrastructures.
Timber was used as a building material even by primitive man, and a few ancient temples, palaces and bridges built of wood can still be seen today. In the 20th century, although materials such as concrete had become competitive, wood retained its significant role in building. The main problem with the use of wood as a construction material concerns its possibly limited lifetime. Wood is characterized by a limited resistance to moisture and fire, the two elements responsible for the destruction of most wooden buildings in the past.
Cement, and consequently concrete, is the most often used material today. The term “cement” is now used to mean a modern binder, the so-called Portland cement, patented in England in 1824. Similar binding materials were already being used from very early on ancient Mesopotamia, Egypt, Greece and Rome. Modern cement formulations have changed a great deal and can be adapted to their intended use and the surrounding environment.
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DiDomenico, Charles F. "The role of engineering graphics in the civil engineering technology curriculum". [Denver, Colo.] : Regis University, 2009. http://adr.coalliance.org/codr/fez/view/codr:123.
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Fumis, Cristiana. "Mechanical Wave Propagation in Civil Engineering Materials". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
Cerca il testo completoAbstract (sommario):
Mechanical wave propagation in civil engineering materials is important for different application fields, such as thermal conductivity, damage detection and sound transmission (including filters and sound barriers). A current open challenge is to understand how the chemistry and microstructures of cementitious materials impact the propagation of mechanical waves in them.
The challenge is heightened by the fact that cementitious materials are very heterogeneous at the microscale. In this project, molecular and nanoparticle based simulations will be used in order to construct microstructures of cement hydrates with a range of chemistries and morphologies. I will simulate the dynamic behaviour of these model structures and quantify it in terms of vibrational band structure and density of states. This will open
the way to a new and fundamental understanding of how the chemistry and microstructure of cementitious materials can be tailored in order to engineer their vibrational behaviour, for controlled thermal conductivity, soundroof applications, and more efficient damage detection.
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Cotela, Dalmau Jordi. "Applications of turbulence modeling in civil engineering". Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/383754.
Testo completoAbstract (sommario):
This thesis explores the use of stabilized finite element formulations for the incompressible Navier-Stokes equations to simulate turbulent flow problems. Turbulence is a challenging problem due to its complex and dynamic nature and its simulation if further complicated by the fact that it involves fluid motions at vastly different length and time scales, requiring fine meshes and long simulation times. A solution to this issue is turbulence modeling, in which only the large scale part of the solution is retained and the effect of smaller turbulent motions is represented by a model, which is generally dissipative in nature.
In the context of finite element simulations for fluids, a second problem is the apparition of numerical instabilities. These can be avoided by the use of stabilized formulations, in which the problem is modified to ensure that it has a stable solution. Since stabilization methods typically introduce numerical dissipation, the relation between numerical and physical dissipation plays a crucial role in the accuracy of turbulent flow simulations. We investigate this issue by studying the behavior of stabilized finite element formulations based on the Variational Multiscale framework and on Finite Calculus, analyzing the results they provide for well-known reference problems, with the final goal of obtaining a method that both ensures numerical stability and introduces physically correct turbulent dissipation.
Given that, even with the use of turbulence models, turbulent flow problems require significant computational resources, we also focused on programming and implementation aspects of finite element codes, specially in ensuring that our solver can perform efficiently on distributed memory architectures and high-performance computing clusters.
Finally, we have developed an adaptive mesh refinement technique to improve and optimize unstructured tetrahedral meshes, again with the goal of enabling the simulation of large turbulent flow problems. This technique combines an error estimator based on Variational Multiscale principles with a simple refinement procedure designed to work in a distributed memory context and we have applied it to the simulation of both turbulent and non-Newtonian flow problems.Aquesta tesi estudia la possibilitat d'utilitzar formulacions estabilitzades d'elements finits de les equacions de Navier-Stokes incompressibles per a la simulació de problemes de flux turbulent. La descripció de la turbulència és un repte, ja que es tracta d'un problema altament dinàmic i complex i la seva simulació numèrica es veu complicada pel fet que hi intervenen moviments de masses fluides amb dimensions i temps característics molt diferents i per tant requereix malles de càlcul molt fines i temps de simulació llargs. Això s'ha provat de resoldre mitjançant l'ús de models de turbulència, mantenint únicament la part de la solució de més gran escala i introduint un model de l'efecte dels moviments de petita escala, que acostuma a tenir un efecte dissipatiu. En el context de la simulació de fluids amb elements finits es planteja un segon problema amb l'aparició d'inestabilitats numèriques. Aquestes es poden evitar amb l'ús de formulacions estabilitzades, en les quals el problema es modifica per assegurar que tingui una solució estable. Ja que els mètodes d'estabilització típicament introdueixen dissipació addicional, la relació entre la dissipació numèrica i la dissipació física té un paper fonamental en la qualitat de la solució. Per investigar aquest fenomen hem estudiat el comportament de diferents formulacions d'elements finits basades en mètodes variacionals de subescala (VMS) i en el càlcul finit (FIC) en termes del seu comportament en la simulació de problemes turbulents de referència, amb l'objectiu final de trobar un mètode que a la vegada garanteixi l'estabilitat de la solució i introdueixi la dissipació turbulenta físicament necessària. Tenint en compte que, fins i tot quan s'utilitzen models de turbulència, la simulació de problemes de flux turbulent requereix molts recursos de càlcul, també hem estudiat aspectes de la implementació paral·lela de programes d'elements finits per tal de garantir que el nostre codi pot treure partit d'arquitectures de memòria distribuïda i servidors de càlcul d'alt rendiment. Finalment, hem desenvolupat una tècnica de refinament adaptatiu de malla que permeti millorar la qualitat de malles de càlcul tetraèdriques, novament amb la intenció de facilitar la simulació de grans problemes de flux turbulent. Aquesta tècnica combina un estimador d'error basat en els principis de la formulació variacional de subescala amb un procediment de refinament dissenyat per funcionar fàcilment en un context de memòria distribuïda i s'ha utilitzat per simular problemes de flux turbulent i no-Newtonià.
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Chuang, Poon-Hwei. "Fuzzy mathematical programming in civil engineering systems". Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/7802.
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Gray, Derrick. "Applications of radiation physics in civil engineering". Thesis, University of Surrey, 1999. http://epubs.surrey.ac.uk/842854/.
Testo completoAbstract (sommario):
This thesis presents two separate applications of ionising radiation in Civil Engineering. The first is an investigation to determine the cement content of concrete using gamma-rays from the naturally occurring isotopes 238U, 232Th and their decay chains as well as 40K. Two sets of equations are derived and discussed. Spectra from cement, aggregate and concrete samples were made and the useful full energy peaks from the above sources identified. Two concrete samples were prepared using the same cement, but, containing two different aggregates: a granite based aggregate and a flint based aggregate. A third concrete sample was then prepared where the cement content was not initially known. Data from the first two tests was then used to determine the mass of cement used in the blind test. A great deal of valuable information has also been accrued concerning the interaction of statistical errors in the equations for the prediction of cement content. Spectra from four different cements were collected at regular intervals over a 24 month period and the variation in the activity of each cement over this period is discussed. The second section of this work presents an imaging technique that uses pair production annihilation photons to examine the state of steel reinforcement in concrete structures. Computer simulations along with experimental work have been used. The experimental work used a 226Ra needle as a photon source as it provided a range of gamma-rays with energies over the pair production threshold of 1022keV. A 31mm rebar with 30mm of concrete cover was successfully located during the experimental work. The data collected from the computer simulations has shown that the geometry and the material between the photon source, rebar and detector is of great importance.
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Watts, Jacqueline Halina. "Women in civil engineering : continuity and change". Thesis, Middlesex University, 2003. http://eprints.mdx.ac.uk/6730/.
Testo completoAbstract (sommario):
This thesis explores the career experiences of women civil engineers in the UK and examines how women negotiate their place in a highly male-dominated profession. T he thesis considers why women are under-represented in this profession, are rarely appointed to senior management positions and how changes in the business pattern of UK engineering consulting companies has created barriers or opportunities for women. Uncovering the detail of women's career expectations and experience was more suited to a qualitative approach to data collection. .A series of semi-structured interviews was carried out with thirty-one women engineers working in different sectors of the profession. The women were in a variety of personal circumstances, including single and married women, some with young children and others with no dependent caring responsibilities. The ages of the women ranged from twenty three to fifty six years with the majority having attained chartered status. The interviews focused on factors that affect career progression and these were discussed within the three themes of subcultures of the profession, work/life balance and possible agents for change. Quantitative membership data from the Institution of Civil Engineers (ICE) and other construction professions has been analysed to provide the context for the research. Feminist concerns about the relationship between women's role in the private sphere of the home and the public sphere of paid work have led to a theoretical framework that draws mainly on the work of Walby and Cockburn. This has been enhanced by Greed's gendered critique of the wider construction sector. The findings show that women feel isolated within the profession and t his isolation seems more pronounced for the few women who reach the top and also generally in the setting of the construction site. Despite attempts by some contracting firms to reform the culture of construction sites, this sense of isolation is heightened by problems of harassment in that setting. .Thus, for many women the prospect of working on site is still very daunting. .Equal opportunities policies have a low profile in the industry and this research shows that women working as professionals in construction do not see' equality' measures of this type as likely agents for change. The image of the profession as predominantly a 'male preserve' continues. and the ICE is regarded as a 'very male club' which admits women only reluctantly. Although women report feeling marginalised within the profession many receive personal support from individual male and female colleagues and this factor can be critical to their career progress. Moving into management is seen as necessary for career success but some women are ambivalent about the negative impacts this may have on work/life balance. The culture of long hours is dominant and this marginalises women with caring commitments and reinforces male hierarchy within the profession.
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Rentzos, Panagiotis. "Active vibration control of civil engineering structures". Thesis, City University London, 2007. http://openaccess.city.ac.uk/8571/.
Testo completoAbstract (sommario):
This thesis is in the area of active vibration control of Civil Engineering structures subject to earthquake loading. Existing structural control methods and technologies including passive, active, semi-active and hybrid control are first introduced. An extensive analysis of a frame-pendulum model is developed and analysed to investigate under what conditions effective energy dissipation is achieved in Tuned Mass Damper systems and the limitation of these devices under stiffness degradation when the structure enters the inelastic region. Linear Quadratic Gaussian and H-infinity active control schemes are designed, simulated and assessed for buildings, modelled as lumped parameter systems, including base and actuator dynamics. Various aspects of the designs are extensively evaluated using multiple criteria and loading conditions and validated in large-scale benchmark problems under practical limitations and implementation constraints. A novel design method is proposed for minimising peak responses of regulated signals via a deadbeat parametrisation of all stabilising controllers in discrete-time. The method incorporates constraints on the magnitude and rate of the control signal and is solved via efficient Linear Programming methods. It is argued that this type of optimisation is more relevant for structural control, as failure occurs when maximum member displacements are exceeded. The problem of stiffness matrix estimation from experimental data is formulated as an optimisation problem and solved under various conditions (positive definiteness, tridiagonal structure) via an alternating convex projection scheme. Both static and dynamic loading is considered. The method is finally incorporated in an adaptive control scheme involving the redesign in real-time of an LQR (Linear Quadratic Regulator) active vibration controller. It is shown that the method is successful in recovering the stability and performance properties of the nominal design under conditions of significant uncertainty in the stiffness parameters.
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Wright, Matthew Joseph. "Canadian civil engineering and sustainable development competence". Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46505.
Testo completoAbstract (sommario):
This study evaluated the importance of sustainable development competence for the civil engineering industry in British Columbia, Canada. Two central research questions were addressed. What is the current civil engineering industry understanding of sustainable development in the areas of knowledge, skills and attitudes? How important are sustainable development competencies for new engineering graduates, and how does this differ across various sectors?
Data were collected from semi-structured interviews of sustainable development practitioners and the administration of a province-wide industry survey. The survey received qualified responses from industry representatives across multiple subdisciplines. The results of the research study have similar findings to previous research studies of sustainable development competence. Practitioners view engineering design, systems thinking and interdisciplinary teamwork as critical areas of competence. Discipline and firm size can contribute to significant level of importance for various competence areas.
Two major themes emerged from the semi-structured interviews. These were categorized as mentorship and reputation, and were described as guiding principles of engineering practice. Minor themes were also noted, and included importance of communication and collaboration across engineering practice. Participants of both the interviews and survey indicated a growing concern for the work readiness of new Engineering graduates while remaining optimistic for the engineering profession.
The diverse sustainable development competencies required of the civil engineering profession is cause for a re-examination of the civil engineering curriculum in Canada. There is evidence to suggest that students are facing a large learning curve entering the profession due to inadequate training course opportunities at the undergraduate level. Higher education institutions should be finding solutions to bridge the gap between industry and accreditation expectations of engineering graduates. Engineering education must adapt to meet the demands of the engineering profession as it continues to prioritize sustainable development as a fundamental requirement of engineering activities.
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Radford, Todd C. (Todd Craig) 1977. "Wireless nodal sensing for civil engineering systems". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/85747.
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Rytter, Anders. "Vibrational based inspection of civil engineering structures /". Online version, 1993. http://bibpurl.oclc.org/web/25073.
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Shafieezadeh, Abdollah. "Application Of Structural Control For Civil Engineering Structures". DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/142.
Testo completoAbstract (sommario):
This study presents the application of control methods in seismic mitigation of structural responses. The study consists of two parts. In the first section, fractional order filters are utilized to enhance the performance of the conventional LQR method for optimal robust control of a simple civil structure. The introduced filters modify the state variables fed back to the constant gain controller. Four combinations of fractional order filter and LQR are considered and optimized based on a new performance criterion defined in the paper. Introducing fractional order filters is shown to improve the results considerably for both the artificially generated ground motions and previously recorded earthquake data. In the second part, frequency dependent filters are introduced to improve the effectiveness of active control systems designed to mitigate the seismic response of large scale civil structures. These filters are introduced as band pass pre-filters to the optimally designed H2/LQG controller to reduce the maximum singular value response of input-output transfer matrices over a defined frequency range. Furthermore, a structured uncertainty model is proposed to evaluate robustness of stability and performance considering nonlinear force-deformation behavior of structures. The proposed perturbation model characterizes variations in the stiffness matrix more accurately, thereby reducing overconservatism in the estimated destabilizing perturbations. The aforementioned techniques are applied to the nonlinear SAC three story steel building. Numerical results indicate that introducing filters can enhance the performance of the system in almost all response measures, while preserving robustness of stability and performance.
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Lentz, Albrecht. "Acceptability of civil engineering decisions involving human consequences". [S.l.] : [s.n.], 2007. http://mediatum2.ub.tum.de/doc/618431/document.pdf.
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Ramokolo, Bruce Sabelo Mpumelelo. "The capacity of emerging civil engineering construction contractors". Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/873.
Testo completoAbstract (sommario):
Construction management competencies are essential to realise sound practices among and to realise optimum performance by, inter alia, emerging civil engineering contractors. Such competencies enable a clear focus on the business of construction and the management of projects, with increased efficiency and reduced costs as a benefit. The objective of the MSc (Built Environment) treatise study were to determine the current practices and performance of emerging civil engineering construction contractors operating in the Nelson Mandela Bay Metropole. The descriptive method was adopted in the empirical study. The salient findings of the study are: most of the emerging civil engineering construction contracting organisations lack construction management competencies; construction resources are inappropriately managed leading to construction failures; most of the emerging civil engineering construction contracting organisations lack adequate supervision resulting to poor workmanship; there is a shortage of skilled labour amongst emerging civil engineering construction contractors; procurement processes are inappropriate leading to under capacitated emerging civil engineering construction contracting organisations being awarded contracts; most emerging civil engineering construction contracting organisations lack the requisite aptitude for construction; there is a lack of capacity at all management levels of emerging civil engineering construction organisations in managing the business of construction and that of projects; the nine functions of organisations are not comprehensively represented, and self-ratings indicate inadequacy relative to the management function of control, and relative to certain activities of the organising function. Conclusions include that emerging civil engineering construction contracting organisations need to be comprised of technical teams that possess adequate competencies and that use the construction technology to its full use enabling their organisations to stay abreast of their competitors. Recommendations that can contribute towards improving the status quo include: formal civil engineering and construction management education, resources must be present and training should be promoted throughout the industry at all levels of management to ensure proper supervision and correct use of adequately trained labour, skilled or semi-skilled, incapacitated emerging civil engineering construction contractors should be awarded contracts through appropriately and structured procurement procedures, adequate aptitude in construction should be promoted and enhanced in order to realise conceptualisation and visualisation capabilities, comply with legislation, maintain records and communicate using state of the art technology, optimally manage the finances, have the requisite resources and undertake the work efficiently, interact with the respective publics, and market the organisation to ensure sustainability thereof.
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Hope, Victoria. "Applications of seismic transmission tomography in civil engineering". Thesis, University of Surrey, 1993. http://epubs.surrey.ac.uk/842729/.
Testo completoAbstract (sommario):
The principles of tomography are well-established, and geotomography has been in use for several decades. Seismic tomography has previously been used principally in the oil and nuclear industries, but it has occasionally been applied in civil engineering site investigation (SI). The technique can provide a qualitative or a quantitative representation of the distribution of the seismic velocity properties within a surveyed region. Seismic tomography has been successfully used to image, for example, zones of fracturing. The technique has been less successful when used to detect cavities. This thesis presents a theoretical and experimental examination of the usefulness - or otherwise - of seismic tomography in SI. It is found that geotomography has a role to play when one is interested in, for example, general subsurface variability. An explanation is offered for the low success rate of cavity detection surveys utilizing seismic velocity tomography. It is shown that, of the numerous and diverse fields of application of the tomographic method, geotomography offers what is, perhaps, the most inherently ill-posed form of the reconstruction problem. Significant difficulties are encountered because, in general, measurements can be acquired from only a restricted set of positions. Additional problems are introduced through the use of seismic wave energy, which follows hard-to-predict routes across the surveyed zone. Observational errors lead to inconsistencies within a tomographic system. In consequence, the geotomographic reconstruction problem is typically under-determined, inconsistent and non-linear. An heuristic method of reconstructing seismic velocity tomograms from typical field data is developed and presented.
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Hofgård, Daniel, e John Sundkvist. "Climate enhanced concrete in the civil engineering industry". Thesis, KTH, Betongbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278216.
Testo completoAbstract (sommario):
In 2017, the Swedish Parliament stated a new climate law with the goal that Sweden should be climate neutral by 2045. The concrete industry has developed a roadmap on how the goal for 2045 can be achieved, where one way to reduce the carbon emissions from concrete is by replacing a part of the cement clinker with alternative binders in the concrete mix. Ground granulated blast furnace slag (GGBS), fly ash, silica fume and trass are alternative binders that are possible to use in concrete mixes to reduce the amount of ordinary Portland cement (OPC). GGBS, fly ash and silica fume are by-products from other industries, while trass is volcanic ash that can be extracted. Besides the positive environmental impact that comes from using alternative binders and reducing the amount of cement clinker, the alternative binders have other properties, both positive and negative, that affect the concrete. The aim of this thesis was to investigate whether concrete with alternative binders does fulfill the regulations set by Swedish standards and how concrete with alternative binders does affect the material parameters. The concrete mixes were divided into three different types of concrete: concrete for bridges (w/c ratio 0.4), hydropower structures (w/c ratio 0.45) and wind powerplant foundations (w/c ratio 0.55). A total of seven concrete mixes were cast in a laboratory and the concrete mixes were investigated in the three hardening stages of concrete: fresh, young and hardened. The analyzed material parameters were compressive strength, shrinkage, frost resistance, workability, air voids and temperature development. Beyond the experimental testing, a global warming potential (GWP) comparison was made to compare the reduction of GWP for each concrete mix compared to a reference concrete for each usage area. The mix containing a CEM II/A-V fly ash cement and 15% GGBS showed great potential regarding the different material parameters. This mix, however, is according to Swedish standards not possible to certify for structures in exposure class XF4, such as bridges, but is possible to certify for structures in exposure class XF3, such as wind powerplant foundations. The mix containing 30% GGBS and 5% silica fume also showed beneficiary properties, but superplasticizers are required in this mix to ensure good workability. For hydropower structures, the mix containing 35% GGBS showed a great compressive strength but a high temperature development and low workability. The mix containing trass had a notably low temperature development, but with an increase in shrinkage and low workability. Moreover, all concrete mixes showed a frost resistance which, according to standard, is classified as “Very Good”.Sveriges regering antog 2017 ett nytt klimatpolitiskt ramverk med målet att Sverige ska ha noll nettoutsläpp av växthusgaser år 2045. Betongindustrin har tagit fram en färdplan för hur betong kan bli klimatneutralt, där ett sätt att reducera klimatpåverkan från betong är att byta ut en del av cementklinkern mot alternativa bindemedel. Mald granulerad masugnsslagg (GGBS), flygaska, silikastoft och trass är alternativa bindemedel som är möjliga att använda i betongblandningar för att reducera mängden Portlandcement. GGBS, flygaska och silikastoft är restprodukter från andra industrier medan trass är en vulkanisk aska som kan utvinnas. Utöver den positiva miljöeffekten som erhålls när alternativa bindemedel ersätter cementklinker, så har de alternativa bindemedlen andra egenskaper, både positiva och negativa, som påverkar betongen. Målet med denna studie var att undersöka och jämföra om betongblandningar där en del av cementklinkern har ersatts med alternativa bindemedel når upp till de krav som ställs i nuvarande regelverk. Utöver det så undersöktes även hur betongblandningarnas materialparametrar påverkades av alternativa bindemedel. Betongblandningarna delades in i tre olika typer av betong: betong för broar (vct 0.4), vattenbyggnader (vct 0.45) och vindkraftverksfundament (vct 0.55), där totalt sju betongblandningar tillverkades i ett laboratorium. Betongblandningarna undersöktes i de tre olika faserna för hårdnande av betong, vilka är färsk, ung och hårdnad betong. De materialparametrar som analyserades var tryckhållfasthet, krympning, frostresistens, arbetbarhet, luftporhalt och temperaturutveckling. Förutom de experimentella testerna gjordes en jämförelse kring hur mycket koldioxid som kan reduceras för varje betongblandning, jämfört med en referensbetong för varje användningsområde. Betongblandningen med ett CEM II/A-V flygaska-cement och 15% GGBS visade stor potential med avseende på de olika materialparametrarna. Denna blandning är dock enligt svensk standard inte möjlig att certifiera för betongbyggnad i exponeringsklass XF4, exempelvis broar, men kan certifieras för betongbyggnad i exponeringsklass XF3, exempelvis fundament för vindkraftverk. Blandningen med 30% GGBS och 5% silikastoft visade även positiva egenskaper, men flyttillsatsmedel måste användas i denna blandning för att erhålla en god arbetbarhet. För vattenbyggnadsbetong så visade blandningen med 35% GGBS en hög tryckhållfasthet, men samtidigt en hög temperaturutveckling och en låg arbetbarhet. Blandningen med trass hade en noterbart låg temperaturutveckling, men med ökad krympning samt låg arbetbarhet. Avslutningsvis så uppvisade alla blandningar en frostresistens som enligt standard klassificeras som ”Mycket bra”.
29
Callcott, A. E. "Microcomputers for civil engineering consultancy in developing countries". Thesis, Aston University, 1985. http://publications.aston.ac.uk/14250/.
Testo completoAbstract (sommario):
The civil engineering industry generally regards new methods and technology with a high amount of scepticism, preferring to use traditional and trusted methods. During the 1980s competition for civil engineering consultancy work in the world has become fierce. Halcrow recognised the need to maintain and improve their competitive edge over other consultants. The use of new technology in the form of microcomputers was seen to be one method to maintain and improve their repuation in the world. This thesis examines the role of microcomputers in civil engineering consultancy with particular reference to overseas projects. The involvement of civil engineers with computers, both past and present, has been investigated and a survey of the use of microcomputers by consultancies was carried out, the results are presented and analysed. A resume of the state-of-the-art of microcomputer technology was made. Various case studies were carried out in order to examine the feasibility of using microcomputers on overseas projects. One case study involved the examination of two projects in Bangladesh and is used to illustrate the requirements and problems encountered in such situations. Two programming applications were undertaken, a dynamic programming model of a single site reservoir and the simulation of the Bangladesh gas grid system. A cost-benefit analysis of a water resources project using microcomputers in the Aguan Valley, Honduras was carried out. Although the initial cost of microcomputers is often small, the overall costs can prove to be very high and are likely to exceed the costs of traditional computer methods. A planned approach for the use of microcomputers is essential in order to reap the expected benefits and recommendations for the implementation of such an approach are presented.
30
Edrees, Tarek. "Structural Control and Identification of Civil Engineering Structures". Doctoral thesis, Luleå tekniska universitet, Byggkonstruktion och -produktion, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18700.
Testo completoAbstract (sommario):
In general, the main purpose of a structural control system is to apply powerful control techniques that improve the behaviour of civil structures under various kinds of dynamic loading. The first part of this thesis presents novel applications of posicast and input shaping control schemes that have never previously been applied in the field of structural control. Numerical simulations of a benchmark three-story building with an MR damper are used to verify the efficiency of the proposed control theories. The superiority and effectiveness of the suggested schemes at reducing the structure’s responses were demonstrated using six evaluation criteria and by comparison to results achieved with well-established classical control schemes. Moreover, a comprehensive procedure for generating scaled real ground motion records appropriate for a seismic analysis and design of structures using the linear spectrum matching technique is presented based on a seismic hazard study.To efficiently control a structure, it is necessary to estimate its real-life dynamical behaviour. This is usually done using the Structural Identification approach, which is also addressed in this thesis. Structural Identification is commonly utilized to bridge the gap between the real structure and its modeled behaviour. It can also be used to evaluate the structure’s health, detect damage, and assess efficiency. Despite the extensive development of parametric time domain identification methods, their relative merits and the accuracy with which they predict the behaviour of vibrating structures are largely unknown because there have been few comparative studies on their performance under diverse test conditions, and they have not been verified against real-life data gathered over extended periods of time.Thus, the second part of this thesis focuses on applications of parametric and non-parametric models based on the Structural Identification approach in order to clarify their potential and applicability. In addition, a new strategy is proposed that combines this approach with techniques based on Singular Value Decomposition (SVD) and Complex Mode Indicator Function (CMIF) curves to detect structural damage.The methods developed in this work are used to predict the vertical frequencies of the top storey in a multi-storey building prefabricated from reinforced concrete in Stockholm, and to detect and locate damage in a benchmark steel frame. In addition, the non-parametric structural identification approach is used to investigate variation in the modal characteristics (frequency, damping, and mode shapes) of a steel railway bridge.Godkänd; 2015; 20150303 (taredr); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Tarek Edreees Saaed Alqado Ämne: Konstruktionsteknik/Structural Engineering Avhandling: Structural Control and Identification of Civil Engineering Structures Opponent: Professor Francesc Pozo, Department of Applied Mathematics III, Escola Universitària d’Enginyeria Tècnica Industrial de Barcelona (EUETIB), Universitat Politècnica de Catalunya Comte d’Urgell, Barcelona, Spanien Ordförande: Professor Jan-Erik Jonasson vid Avd för byggkonstruktion och produktion, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Torsdag den 26 mars 2015, kl 10.00 Plats: C305, Luleå tekniska universitet
31
Bakht, Agha Bedar. "Engineering Leadership Competencies for Entry-Level Civil Engineers". ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/6165.
Testo completoAbstract (sommario):
The general problem is that while technical engineering firms today require entry-level, full-time engineers to possess leadership skills, companies have failed to indicate which leadership competencies are most important in their recruitment and hiring process. This study's contributions could have implications for the long-term career prospects of engineers as well as the future outlook and sustainability of engineering companies. The specific problem is that various disciplines in the engineering profession, such as the construction sector, have yet to clearly define which leadership competencies are most important for the job market in their specific areas. Advancements in this regard are important for both entry-level engineers and engineering companies given the strong competition in local and international markets. The purpose of this qualitative study using a multiple case study design was to explore the views of managers in the construction industry on leadership competencies most needed in the job market for entry-level civil engineers. The study was framed by three concepts of engineering leadership. The research question was: How do the perceptions of managers in the construction industry establish a basis of leadership competencies most needed in the job market for entry-level civil engineers? Applying the knowledge gained from this inquiry has the potential for positive social impact by driving reforms in educational curricula and professional settings and with industry leaders to further the personal development of early-stage civil engineers, supporting their career success and the success of their companies.
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Bush, Sarah 1973. "Integrating engineering education". Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47457.
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Alahmed, Salman. "Civil Affairs in Saudi Arabia". Digital Commons at Loyola Marymount University and Loyola Law School, 2015. https://digitalcommons.lmu.edu/etd/352.
Testo completoAbstract (sommario):
In Saudi Arabia the wait at a Civil Affairs office (Figure 1 ), the equivalent of the U.S. Department of Motor Vehicles, can reach up to several hours these days. Visitors must plan to surrender their mornings or afternoons in order to attend to their Civil Affairs business. Something urgently needs to be done about this. A more efficient and effective system is needed. The solution might be an online computerized approach which allows visitors to address their needs directly. This approach would ensure legitimacy and credibility while meeting obligations to the Civil Affairs. The system would allow input from, and responses to, the Civil Affairs office. The system being considered has · six parts that interact electronically to rapidly process customer requests and direct the requests to the most appropriate destinations. This six-part concept will be an improvement over the greatly challenged, outdated system that has plagued the Saudi Kingdom for too long. The whole process, from beginning to end, will take only a few hours. However, the system will certainly be better than waiting in line for three or four hours. The system does not require the user to take time off from work, neglecting one's children, nor even leave one's home. The system is fully automated and will appreciably lessen work loads.
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Alias, Maizam. "Spatial visualisation ability and problem solving in civil engineering". Thesis, Online version, 2000. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.325666.
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Pan, Qin Aktan A. E. "System identification of constructed civil engineering structures and uncertainty /". Philadelphia, Pa. : Drexel University, 2007. http://hdl.handle.net/1860/2531.
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36
Capra, Mauricio. "Collaborative mixed reality environments : an application for civil engineering". Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/11103/.
Testo completoAbstract (sommario):
The present thesis designs, implements and evaluates a channel for interaction between office and field users through a collaborative mixed reality system. This channel is aimed to be used for civil engineering purposes and is thus oriented toward the design and construction phases. Its application should contribute to the reduction of the challenges faced by those involved in a civil engineering project dealing with communication, collaboration and mutual understanding. Such challenges can become real problems for multidisciplinary teams of architects, engineers and constructors when working on the same project. In the context of this thesis, outdoor users are equipped with a real-time kinematic global positioning system receiver, a notebook, a head-mounted display, a tilt sensor and a compass. A virtual environment representing components of a civil engineering project is displayed before their eyes. Outdoor users share this collaborative virtual environment with indoor ones. They can talk to and see each other through an avatar. Indoor users can take part from any location where Internet is available. The goal of this thesis is to show that a networked solution of at least two users (In this case, indoor and outdoor users) is an opportunity for outdoor users to perform complex tasks whilst experiencing an immersive augmented reality application. Indoor users interact with outdoor ones when handling and navigating the virtual environment, guiding their counterpart through the scene and making clear common points of understanding. The thesis evaluates how users interact within a prototype system using a formative approach. Users are introduced to the system and motivated to “talk loudly”, thus verbalising what they are experiencing during the tests. All users are video-recorded while performing the exercises and interviewed immediately after. The evaluation reveals that users end up experiencing a system that is too immersive, which ends up narrowing their “attentional spotlight” to the virtual environment and not, as desired, experiencing an augmented reality system. The evaluation also makes clear that the design of the virtual environment is eventually more important for users than the system itself, and it is completely the kind of application that it is being used to and who the users are.
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Ayhan, Tezer Bahar. "Damage evaluation of civil engineering structures under extreme loadings". Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2013. http://tel.archives-ouvertes.fr/tel-00975488.
Testo completoAbstract (sommario):
In many industrial and scientific domains, especially in civil engineering and mechanical engineering fields, materials that can be used on the microstructure scale, are highly heterogeneous by comparison to the nature of mechanical behavior. This feature can make the prediction of the behavior of the structure subjected to various loading types, necessary for sustainable design, difficult enough. The construction of civil engineering structures is regulated all over the world: the standards are more stringent and taken into account, up to a limit state, due to different loadings, for example severe loadings such as impact or earthquake. Behavior models of materials and structures must include the development of these design criteria and thereby become more complex, highly nonlinear. These models are often based on phenomenological approaches, are capable of reproducing the material response to the ultimate level. Stress-strain responses of materials under cyclic loading, for which many researches have been executed in the previous years in order to characterize and model, are defined by different kind of cyclic plasticity properties such as cyclic hardening, ratcheting and relaxation. By using the existing constitutive models, these mentioned responses can be simulated in a reasonable way. However, there may be failure in some simulation for the structural responses and local and global deformation. Inadequacy of these studies can be solved by developing strong constitutive models with the help of the experiments and the knowledge of the principles of working of different inelastic behavior mechanisms together. This dissertation develops a phenomenological constitutive model which is capable of coupling two basic inelastic behavior mechanisms, plasticity and damage by studying the cyclic inelastic features. In either plasticity or damage part, both isotropic and linear kinematic hardening effects are taken into account. The main advantage of the model is the use of independent plasticity versus damage criteria for describing the inelastic mechanisms. Another advantage concerns the numerical implementation of such model provided in hybrid-stress variational framework, resulting with much enhanced accuracy and efficient computation of stress and internal variables in each element. The model is assessed by simulating hysteresis loop shape, cyclic hardening, cyclic relaxation, and finally a series of ratcheting responses under uniaxial loading responses. Overall, this dissertation demonstrates a methodical and systematic development of a constitutive model for simulating a broad set of cycle responses. Several illustrative examples are presented in order to confirm the accuracy and efficiency of the proposed formulation in application to cyclic loading.
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Nienaber, Jacobus Andries. "Transformation in the civil engineering industry / Jacobus Andries Nienaber". Thesis, North-West University, 2008. http://hdl.handle.net/10394/2887.
Testo completoAbstract (sommario):
Transformation in the civil consulting engineering industry has been addressed, but there are still some shortcomings. This transformation is based on Broad-Based Black Economic Empowerment, Affirmative Action and Employment Equity.
> The main aim of Broad-Based Black Economic Empowerment is to redress historical inequalities in such a manner that it does not impact negatively on existing enterprises.
> The aim of Affirmative Action is to promote equal opportunity and fair treatment in employment through the elimination of unfair discrimination and the implementation of Affirmative Action measures. The aim is to redress the disadvantages in employment experienced by designated groups in order to ensure their equitable representation in all occupational categories and levels of the workforce.
> The main aim of Employment Equity is to promote equal opportunity and fair treatment in employment through the elimination of unfair discrimination and to redress the disadvantages in employment experienced by designated groups.
The existing drive to successfully implement transformation in the Civil Consulting Engineering Sector creates the opportunities for suitably qualified and experienced black engineering candidates to be selected for appointment above an equally qualified and experienced white candidate who applies for the same position. Although Civil Engineering as we know it in South Africa is only 105 years old, it has a rich history and contributed substantially to turning South Africa into a jewel and economic hub on the African continent.
The Civil Consulting Engineering Sector forms part of the Construction Sector and abides by the set of rules that has been compiled for the construction sector, known as the Construction Sector - Broad-Based Black Economic Charter - Version 6, 2006. This Construction Sector - Broad-Based Black Economic Charter - Version 6 is intended to assist all existing as well as any future businesses or stakeholders by providing a framework for the construction sector to address Broad-Based Black Economic Empowerment, enhance capacity and increase the productivity of the sector to meet world standard.
The Government's strategy or vision is to utilise Broad-Based Black Economic Empowerment as a tool to redress past inequalities and to broaden, expand and increase the country's economic base by including everybody that can participate in and contribute to the South African economy. The envisaged spin-offs from the implementation of this strategy by the Government would be to accelerate economic growth and this would then lead to job creation, and consequent poverty eradication.
The Government intends to achieve Broad-Based Black Economic Empowerment by making use of a balanced approach that includes contributions and measures that will mainly readdress ownership, control, employment equity, skills development, procurement, enterprise development and Corporate Social Development. This approach by Government will further address additional elements as indicated on the Broad-Based Black Economic scorecard. Transformation in the Civil Consulting Engineering Sector is currently hampered by a shortage of suitably qualified and experienced black engineering candidates that can be employed in the Civil Consulting Engineering Sector.
The researcher is also employed in the Civil Consulting Engineering Sector and therefore experiences all the frustrations on a daily basis, which inspired this research to determine the status quo with regard to transformation in the Civil Consulting Engineering Sector.Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2009.
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Mohd, Yunus Mohd Zulkifli. "Geospatial data management throughout large area civil engineering projects". Thesis, University of Newcastle Upon Tyne, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360241.
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40
Stamoulis, Catherine 1968. "Application of statistical fault detection to civil engineering systems". Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12312.
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41
Mahmoud, Mohamed Mostafa. "Contrasting perceptions of an innovation in teaching civil engineering". Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/19092.
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42
RICHARD, DEEPAK. "LIFECYCLE PERFORMANCE MODEL FOR COMPOSITE MATERIALS IN CIVIL ENGINEERING". University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1069787827.
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Zorrilla, Martínez Rubén. "Towards the virtual wind tunnel for civil engineering applications". Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/671768.
Testo completoAbstract (sommario):
This thesis develops a numerical tool (the Virtual Wind Tunnel, VWT) for the resolution of problems involving fluid flow around structures. Due to the limitations that traditional methods may have in this context, the VWT is based on the use of fixed mesh technologies (CutFEM-type) combined with an implicit representation of the embedded bodies.
One of the main contributions of the thesis is the use of such fixed mesh methods to solve lightweight thin-walled structures problems. Hence, two embedded formulations capable of representing the flow around bodies with and without internal volume are proposed. The first one results in a simpler implementation and lower computational effort but can only represent a slip behavior of the wall. The second one gets rid of such limitation by including a Nitsche imposition of the Navier-slip condition, thus allowing modelling any wall behavior as a wall law would do.
The applicability range of the VWT includes the fluid–structure interaction problem (FSI). To that purpose an improvement for the boundary condition imposition of the FM-ALE algorithm mesh motion problem is also proposed. Moreover, the implementation, which has been conceived to be easily extended to any other coupled problem, is also treated.
The validation of the technologies within the VWT includes multiple theoretical test cases as well as feasible industrial applications. Among these, the FSI analysis of a 4-point tent during a strong wind episode deserves to be highlighted as it showcases the achievement of the initial objective of the thesis.En esta tesis se desarrolla una herramienta numérica (el Virtual Wind Tunnel, VWT) para la resolución de problemas que involucran el flujo de un fluido alrededor de una estructura. Debido a las limitaciones que los métodos tradicionales pueden tener en este contexto, el VWT se basa en el empleo de técnicas de malla fija (tipo CutFEM) combinadas con una descripción implícita de los cuerpos embebidos. Una de las principales contribuciones de la tesis es el empleo de dichos métodos de malla fija para resolver problemas de estructuras ligeras de pared delgada. Así pues, se proponen dos formulaciones embebidas capaces de representar el flujo alrededor de un cuerpo con o sin volumen interno. La primera de ellas resulta en una implementación más sencilla así como en un menor coste computacional pero únicamente puede reprentar un comportamiento deslizante de la pared. La segunda elimina esta limitación incluyendo una imposición mediante el método de Nitsche de la condición de Navier-slip, permitiendo así modelar cualquier comportamiento del mismo modo que lo haría una ley de pared. El rango de aplicabilidad del VWT incluye el problema de interacción fluido¿estructura (FSI). A tal propósito se plantea una mejora para la imposición de las condiciones de contorno del problema de movimiento de la malla del algoritmo FM-ALE. Asimismo, también se hace especial hincapié en la implementación, que ha sido concebida para ser fácilmente extensible a cualquier otro problema acoplado. La validación de las tecnologías implementadas en el VWT incluyen múltiples casos teóricos así como posibles aplicaciones industriales. Entre éstas se destaca el análisis FSI de una 4-point tent durante un episodio de viento severo ya que demuestra la consecución del objetivo inicial de la tesis.
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Stone, Gregory M. "Beneficial Reuse of Corrugated Paperboard in Civil Engineering Applications". DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/691.
Testo completoAbstract (sommario):
Abstract
Beneficial Reuse of Corrugated Paperboard in Civil Engineering Applications
Gregory Michael Stone
An investigation was conducted to explore the potential for reuse of corrugated paperboard. Corrugated paperboard represents a large fraction of the municipal solid waste generated and discarded in the United States. Alternative applications for reuse can provide a significant benefit by reducing the volume of waste being disposed and by reducing the use of raw materials. Four civil engineering applications were examined for potential beneficial reuse of corrugated paperboard: slurry trench construction, vertical drilling, directional drilling, and controlled low strength materials (CLSM).
For the purpose of this project, corrugated paperboard was pulped and added to bentonite slurry or CLSM mixtures. Bentonite slurry mixtures were tested for viscosity, density, filtrate loss, and permeability. The behavior of the bentonite slurries was greatly influenced by interaction and interlocking of corrugate fibers; in general resulting in increased viscosity, filtrate loss, and permeability and decreased density. CLSM mixtures were tested for flow consistency, unit weight, air content, and compressive strength. CLSM mixtures prepared with corrugated paperboard showed an increased water demand due to high absorption of the corrugate. The higher water content was a significant factor contributing to decreased unit weight and compressive strength. CLSM mixtures containing corrugated paperboard also exhibited increased air contents, possibly due to entrapment of air within the corrugate pulp.
Corrugated paperboard was used to successfully replace up to 27% of bentonite for slurry trench applications, 60% of bentonite for vertical drilling applications, and 59% of bentonite for directional drilling applications while maintaining acceptable engineering properties. For CLSM mixtures up to 1% of fine aggregate was replaced with corrugated paperboard while maintaining satisfactory engineering properties.
Incorporation of corrugated paper board into bentonite slurry, CLSM, and drilling fluid applications provides a viable option for beneficial reuse.
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Mohy, El Dine Kamal. "Control of robotic mobile manipulators : application to civil engineering". Thesis, Université Clermont Auvergne (2017-2020), 2019. http://www.theses.fr/2019CLFAC015/document.
Testo completoAbstract (sommario):
Malgré le progrès de l'automatisation industrielle, les solutions robotiques ne sont pas encore couramment utilisées dans le secteur du génie civil. Plus spécifiquement, les tâches de ponçage, telles que le désamiantage, sont toujours effectuées par des opérateurs humains utilisant des outils électriques et hydrauliques classiques. Cependant, avec la diminution du coût relatif des machines par rapport au travail humain et les réglementations sanitaires strictes applicables à des travaux aussi risqués, les robots deviennent progressivement des alternatives crédibles pour automatiser ces tâches et remplacer les humains.Dans cette thèse, des nouvelles approches de contrôle de ponçage de surface sont élaborées. Le premier contrôleur est un contrôleur hybride position-force avec poignet conforme. Il est composé de 3 boucles de commande, force, position et admittance. La commutation entre les commandes pourrait créer des discontinuités, ce qui a été résolu en proposant une commande de transition. Dans ce contrôleur, la force de choc est réduite par la commande de transition proposée entre les modes espace libre et contact. Le second contrôleur est basé sur un modèle de ponçage développé et un contrôleur hybride adaptatif position-vitesse-force. Les contrôleurs sont validés expérimentalement sur un bras robotique à 7 degrés de liberté équipé d'une caméra et d'un capteur de force-couple. Les résultats expérimentaux montrent de bonnes performances et les contrôleurs sont prometteurs. De plus, une nouvelle approche pour contrôler la stabilité des manipulateurs mobiles en temps réel est présentée. Le contrôleur est basé sur le « zero moment point », il a été testé dans des simulations et il a été capable de maintenir activement la stabilité de basculement du manipulateur mobile tout en se déplaçant. En outre, les incertitudes liées à la modélisation et aux capteurs sont prises en compte dans les contrôleurs mentionnés où des observateurs sont proposés.Les détails du développement et de l'évaluation des différents contrôleurs proposés sont présentés, leurs mérites et leurs limites sont discutés et des travaux futurs sont suggérésDespite the advancements in industrial automation, robotic solutions are not yet commonly used in the civil engineering sector. More specifically, grinding tasks such as asbestos removal, are still performed by human operators using conventional electrical and hydraulic tools. However, with the decrease in the relative cost of machinery with respect to human labor and with the strict health regulations on such risky jobs, robots are progressively becoming credible alternatives to automate these tasks and replace humans.In this thesis, novel surface grinding control approaches are elaborated. The first controller is based on hybrid position-force controller with compliant wrist and a smooth switching strategy. In this controller, the impact force is reduced by the proposed smooth switching between free space and contact modes. The second controller is based on a developed grinding model and an adaptive hybrid position-velocity-force controller. The controllers are validated experimentally on a 7-degrees-of-freedom robotic arm equipped with a camera and a force-torque sensor. The experimental results show good performances and the controllers are promising. Additionally, a new approach for controlling the stability of mobile manipulators in real time is presented. The controller is based on zero moment point, it is tested in simulations and it was able to actively maintain the tip-over stability of the mobile manipulator while moving. Moreover, the modeling and sensors uncertainties are taken into account in the mentioned controllers where observers are proposed. The details of the development and evaluation of the several proposed controllers are presented, their merits and limitations are discussed and future works are suggested
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Alavi, Toussi Maryam. "Evaluation of factors influencing delay in construction/civil engineering". Thesis, Curtin University, 2015. http://hdl.handle.net/20.500.11937/1908.
Testo completoAbstract (sommario):
Many factors contribute to delay in building work and often such variables are location specific; socio-political flux and knock-on economic regional (re)development issues necessitate construction professionals involved in the estimating process to seek location-specific risk reviews in order to mitigate the potential for construction project-time blow-outs. This research builds upon an identification and analyses of region-specific risk factors to advise region-specific variables on the time-estimates and timing of civil engineering and construction projects.
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Deacon, M. "Distributed Collaboration: Engineering Practice Requirements". Thesis, Linkt to the online version, 2007. http://hdl.handle.net/10019/755.
Testo completo
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Samuels, Fallon M. (Fallon Michele). "Valuable bridges : cable-stayed bridges and value engineering in American civil engineering culture, 1969-1979". Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41760.
Testo completoAbstract (sommario):
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2007.Page 109 blank.
Includes bibliographical references (p. 99-108).
A history and theory of cable-stayed bridges in the context of a cultural discourse on civil construction projects' value, this thesis studies the significance of cable-stayed bridge designs to 'value engineering' objectives for major highway bridge projects of the 1970s. This study of preliminary designs and feasibility studies for highway bridges presents the alternate bridge designs versus alternative bridge typologies selected during this period as one instance of American civil engineering culture adapting to major bridge projects the economically measured but industrial approach to choosing, reconfiguring and eliminating construction systems of value engineering. Only as analytical mechanisms of bridge construction that figure as economically competitive in prevailing market conditions do the high-capital and technologically innovative bridge designs of the Luling Bridge (LA, 1978) and the Pasco-Kennewick Bridge (WA, 1977) develop into physical constructions built almost exclusively with federal highway funds. This shift in cable-stayed bridge designs' fate from abandoned projects in the 1960s is discussed as the reflection of structural engineers' engaging in the post-capitalist practices of analytical and then physical systems building, decision analysis, speculation as well as the interdisciplinary cultures from which these concepts stem. Critical studies of preliminary designs and construction industry data circa 1970 reveal cable-stayed bridge type selections to be at once the linchpin to politicization of VE in American highway bridge building by 1979 and the Achilles heel of an American civil engineering culture that sought a renaissance in bridge engineering not a redefinition of its principles through a new method of planning for alternate futures.
by Fallon M. Samuels.
S.M.
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Fung, Leung Pik-wah. "Strategic human resources management in a civil engineering/construction company /". [Hong Kong] : University of Hong Kong, 1991. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13055045.
Testo completo
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Saliba, Nabil E. "A quantitative approach to structural forensic engineering /". Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82630.
Testo completoAbstract (sommario):
Structural forensic engineering is a topic that has traditionally been approached in a deterministic manner. This thesis explores the use of probabilistic procedures as a tool to obtain more objective and realistic results in forensic investigations. The first goal of the thesis is the identification of the most probable cause of a structural failure using probabilistic procedures. The second goal is to develop a procedure to qualify forensic engineers and experts according to their qualifications.In the first part, the basic qualifications required for a forensic engineer or expert are compiled in a checklist and attributed individual scores, the sum of which qualifies a candidate to act as a forensic engineer or expert. The proposed qualification and scoring checklist is then validated through a survey conducted among professionals with forensic engineering exposures.
The second part quantifies failure modes in terms of their likelihood. The proposed methodology uses a-priori failure probabilities from historic data, elicits forensic engineering experts for subjective failure probabilities, calculates the updated posterior failure probabilities, and identifies the failure cause corresponding to the highest posterior probability as the most plausible cause of failure.
The proposed methodology is supported by a thorough literature review of forensic engineering procedures, a classification of structural failure causes, and expert opinion elicitation and aggregation methods.