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Thesis (Ph. D.)--University of Sydney, 2008. / Title from title screen (December 12, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Architecture, Design and Planning. Includes bibliographical references. Also available in print form.

Thesis (Ed.D.)--Boston University.

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A theory for predicting the dynamic response of earth structures subject to earthquake forces as presented herein. The proposed theory essentially introduces a stress limit into the viscoelastic shear-slice or shear-beam analogy and thus, in essence, the structure is modelled by a multidegree of freedom system which responds in an elastic-viscoplastic manner. The stress limit may be varied with both the magnitude of displacement and the number of stress cycles so that, in practice, a complex stress-strain relationship can be considered in the analysis. The method allows the dynamic displacements, velocities, and accelerations within the structure to be calculated at any time, t, when the base is subjected to a known acceleration. If magnitude of displacements is considered the criterion for earthquake design, then the proposed method of analysis gives a direct measure of these displacements. The analysis is applied to a number of earth structures using a base acceleration corresponding to the 0-10 secs. of El Centro, 1940 earthquake. Displacements, velocities and accelerations are calculated at discreet time intervals. Results are compared with those obtained from a viscoelastic dynamic analysis and it is found that plastic action causes larger displacements and smaller accelerations. The location of plastic yield is dependent on the strength properties of the material. For material of uniform strength, yield will occur essentially at the base of the structure, while for ideal frictional material, yield will take place throughout the structure but will be greatest at the top. Lateral force or seismic,coefficients from viscoelastic and elastic-viscoplastic are compared. Results suggest that the common practice of allowing for plastic-action by assuming some high viscous damping factor such as 20% of critical in a viscoelastic analysis is unlikely to give correct results. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

This thesis presents a conceptual framework for the introduction of daylighting considerations into the design of office buildings. Design is an intuitive process, yet the intuition must be educated by study and analysis. The framework developed in the thesis enables the systematic study of daylighting principles and techniques and is a major step towards a grasp of daylighting design. The thesis is divided into nine chapters. The introductory chapter contains a brief history of daylighting in office buildings, examines reasons for daylighting, and explains the structure of the thesis. The following chapter analyses the performance criteria that the luminous environment in office interiors must fulfill in order to provide a satisfactory performance of visual tasks and result in user acceptance. Each of the next five chapters examine specific techniques, under five general objectives: i. promoting daylight access ii. promoting daylight penetration iii. interior space planning for daylighting advantage iv. controlling brightness extremes v. integrating daylight with electrical light In each chapter, these techniques are listed in order of decreasing scale: from site planning, through building configuration and building envelope, to building interior. The thesis shows that daylighting can be incorporated into building design at various levels of commitment, ranging from a total commitment to daylighting, in which the building is conceived as "a light fixture that can be engineered to a state of optimal performance", to a minor commitment, in which, for example, perimeter lights in an otherwise standard office building design are controlled in response to daylighting needs. Furthermore, it is shown that daylighting techniques can be introduced at various scales--some techniques may modulate the massing, while others deal with specific building components. Following the study of techniques, there is a discussion on daylighting design tools and the integration of daylighting with other aspects of design. The thesis concludes that daylighting offers architects the opportunity to design office buildings so that they use less energy and, at the same time, provide a better working environment than is the case with most buildings today. / Applied Science, Faculty of / Architecture and Landscape Architecture (SALA), School of / Graduate

Among the different environmental functions atria perform, this research has focused only on daylighting. The thesis has been presented in two parts. The first part provides the background information, the extent of daylighting research in atria, objective and scope of the research. The environmental role of atria has also been discussed. The second part deals with the research procedure, the description of the scale model used for the study, the conditions under which the study have been conducted, and finally, the conclusions of the study. The effects of changing the reflectivity of the wall and floor surfaces of the atria well on the illumination in the adjacent spaces to atria have been studied. The objective of the thesis was to establish the relative contributions of the changes in the surface reflectance of the wall and the effects of variations in the area of the openings in the wall facade on lighting in the adjacent occupied spaces. The importance of the floor reflectivity in lighting the spaces adjacent to the atria was also determined. Quantitative analysis of daylighting in atria has been conducted using physical scale models under natural overcast skies using daylight factor and well index to normalize the results. Although the thesis has concentrated on daylighting, in reality there are other functions, both social and environmental, that atria are required to perform, and where appropriate, these functions have been acknowledged. It has been established by this research, that the atria well and the spaces adjacent to it are affected by changes in the area of openings in the form of windows in the wall facades of the well. Small variations in higher reflective surfaces on the wall facade produce greater differences in the daylight factors as compared to similar differences in surfaces with lower reflectances. Using high surface reflectance on the floor of the atria well will enhance illumination in the lower levels of the atria. As the area of the (high) reflective surfaces along the edges of the floor is increased, the illumination in the side spaces in the lower levels also increases. The area of floor reflectivity needed for increasing the illumination levels in the side spaces is dependent on the area of openings on the walls at the lower levels. / Applied Science, Faculty of / Architecture and Landscape Architecture (SALA), School of / Graduate

This thesis studies the effects of model aspect ratio on the static forces and galloping vibrations of bluff shapes when exposed to a turbulent boundary layer similar to the atmosphere. Previous investigations have analyzed the galloping oscillations of finite prismatic bodies exposed to a turbulent shear flow on the basis of the quasi-steady theory and the assumption of an average lateral force. Herein consideration is given to the variation of lateral forces with height and the galloping oscillations of two finite square towers are predicted. The turbulent boundary layer was grown over a long fetch of roughness and at the location of the static and dynamic tests was 28" deep and had properties similar to a suburban or forested full scale exposure. The geometric scale of the models found from an analysis of velocity spectra was about 1/500. For the height to width ratios examined, aspect ratio had little effect on the average static forces for small angles of attack. The local static forces, measured from the pressure distribution, had a wide variation over the height of the model. For the finite sections examined the response predicted from the local forces gave higher amplitudes for the same reduced velocity as compared, to the response found from the average forces. The results of the dynamic tests agreed with the galloping response predicted from the local sectional forces indicating that the three-dimensional effects are important in the consideration of the galloping phenomenon. The measurements of velocity spectra in the wake of the rigid 28" model indicate that the Strouhal shedding frequency varies along the span of the model. Similar velocity spectra behind the galloping 28" model did not exhibit a discernible peak at the stationary value of the Strouhal number. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

This thesis is concerned with the response of multi-story prestressed concrete frames to seismic loading, and the ductility demands of the constituent members. In that regard, an idealized model for the end moment-plastic rotation relationship of prestressed concrete members was developed based on a published moment-curvature idealization for prestressed concrete. The idealized moment-rotation model, which included stiffness and strength degradation, was used to introduce all post-elastic action In a beam-column element, which consisted of an elastic beam connecting concentrated hinges modeled as nonlinear rotational springs. The subsequent use of the element in the nonlinear analysis of a typical multi-story prestressed concrete frame indicated that both the lateral displacements, and the girder end rotational and hinge curvature ductilities would be somewhat higher for a prestressed concrete frame than for a reinforced concrete frame with the same initial stiffness and strength. As an effort to limit deflections, and minimize member damage under moderate seismic loading the use of a higher base shear for a prestressed concrete structure than for a comparable reinforced concrete structure appears warranted. / Applied Science, Faculty of / Civil Engineering, Department of / Unknown