Infrastructure Engineering - Theses
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ItemObject-oriented concepts for land and geographic information systems( 1991)This research studies the impact of Object Oriented Programming Systems (OOPS) and their underlying concepts on Land and Geographic Information Systems (LIS/GIS) in Australasia. This research considers GIS software development and conceptual data modelling aspects, and the strong relationship with proposed spatial data transfer standards. Conventional programming techniques appear to have reached their limit in coping with complex and diversified applications. "Something better' is envisaged for future software developments and data models in LIS/GIS. The relatively new object-oriented design method is reviewed and a much improved object-oriented software module for the daily maintenance operations in a Digital Cadastral Data Base (DCDB) is presented as an example. This development allows a significant improvement of the spatial accuracy of DCDB systems and its graphical user interface (GUI) represents a much better data quality visualisation tool. The choice of the right conceptual data model for GIS has a strong impact on proposed spatial data transfer standards and the way in which future Australian GIS communities will 'view' or model their real world. It has therefore been important to critically review these proposals in the Australian context.
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ItemLarge scale, long term, physically based modelling of the effects of land cover change on forest water yield( 1999)The question was asked: is it possible to realistically and spatially simulate the water balance of forests at large scales for long periods in a way which responds to land cover change. The answer to this question was pursued by attempting to construct a new model and applying it to a 163 km2 catchment area near Melbourne, Australia.
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ItemA one-dimensional Boussinesq-type momentum model for steady rapidly varied open channel flows( 2004-11)The depth-averaged Saint-Venant equations, which are used for most computational flow models, are adequate in simulating open channel flows with insignificant curvatures of streamlines. However, these equations are insufficient when applied to flow problems where the effects of non-hydrostatic pressure distribution are predominant. This study provides a comprehensive examination of the feasibility of a simple one-dimensional Boussinesq-type model equation for such types of flow problems. This equation, which allows for curvature of the free surface and a non-hydrostatic pressure distribution, is derived using the momentum principle together with the assumption of a constant centrifugal term at a vertical section. Besides, two Boussinesq-type model equations that incorporate different degrees of corrections for the effects of the curvature of the streamline are investigated in this work. One model, the weakly curved flow equation model, is the simplified version of the flow model based on a constant centrifugal term for flow situations that involve weak streamline curvature and slope, and the other, the Boussinesq-type momentum equation linear model is developed based on the assumption of a linear variation of centrifugal term with depth.
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ItemThe significance of episodic recharge in the wheatbelt of Western Australia( 2000-11)Groundwater levels in the Wheatbelt of Western Australia are rising and causing severe and widespread land salinisation. Evidence from northern Victoria showed that episodic recharge pulses following floods had caused significant groundwater rises. The aim of this study was to determine: 1. whether episodic recharge was significant compared to regular recharge in the Wheatbelt; 2. the conditions under which episodic recharge occurs. (For complete abstract open document)
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ItemPerformance of steel framed domestic structures subjected to earthquake loads( 1997)This thesis investigates the performance of cold formed steel framed domestic structures subjected to earthquake loads. These structures generally include one and two storey houses, comprising steel wall framing, exterior veneer cladding and internal lining. The dynamic, non-linear performance of such structures during earthquakes is simplified to static linear behaviour for design purposes using the structural response modification factor, Rµ. This factor is defined as the product of the structural ductility reduction factor, Rµ, and the over-strength of the system, Ω. This thesis develops a rigorous technique for the determination of Rµ and the application of this technique is demonstrated for a proprietary framing system. This is achieved using novel non-linear, transient dynamic finite element models of these structures subjected to earthquake loads. The model parameters are estimated from unique experiments conducted on representative structures using a shaking table. It is shown that the framing system considered is non-ductile (ie Rµ≈1). This result directly contradicts the assumed ductile behaviour of these framing systems as specified in the Australian earthquake loading standard, AS 1170.4. The significance of this is that current design practices are unconservative and therefore underestimate the earthquake loads on these structures.
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ItemFull-scale testing, modelling and analysis of light-frame structures under lateral loading( 2002-02)The differing needs and expectations of building owners, users and society are driving a change towards a technology-intensive, performance-based approach to the design and evaluation of light-frame structures. A critical underlying assumption of the performance-based philosophy is that performance can be predicted with reasonable accuracy and consistency. Development of improved performance prediction technologies, for light-frame structures, requires a detailed understanding of the structural behaviour of light-frame buildings, as well as the environmental loadings to which they are subjected during their lifetime. Full-scale structural testing in the laboratory, combined with analytical modelling, are essential in obtaining this understanding. This thesis presents the results of experimental and analytical investigations into the performance of light-frame structures under lateral loading. The specific objectives of this research are to:1)develop simple, experimentally validated numerical models of light-Frame structures, which can be used to predict their performance under lateral loads, particularly seismic loads; and 2) collect experimental data suitable for validation of detailed finite-element models of light-frame structures.
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ItemLow flow hydrology: application of a systems approach( 1990-06)Australia is not only the driest continent, but its streams are among the most variable in the world. To date in Australia there has been no large-scale study of Australia’s low flow hydrologic characteristics, and consequently there is a fundamental need to develop methods that can be readily used to assess the hydrology during times of low flow. This thesis describes the development and derivation of a methodology for the estimation of low flow characteristics and yield in small ungauged rural catchments. The methodology has been applied to 184 catchments located in New South Wales and Victoria, in south-eastern Australia. A systems approach was adopted in which multivariate techniques were used to develop relationships between low flow parameters and climatic and land information data. The low flow and yield parameters considered include: descriptive statistics of monthly and annual flows, ratio of baseflow to total streamflow volumes, streamflow recession constants, flow duration curves for daily, monthly and annual durations, low flow frequency curves for durations from 1 to 284 days, duration of low flow spells below a given threshold, deficiency volume of low flow spells below a given threshold, estimate of storage to satisfy a specified draft at a given level of reliability, and parameters of a simple rainfall-runoff model for conversion of daily rainfall to monthly streamflow volumes.
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ItemPerformance of brick-veneer steel-framed domestic structures under earthquake loading( 1997-11)This project investigates the performance of brick-veneer cold-formed steel-framed domestic structures when subjected to earthquake-induced loads. It focuses on the effects of the so-called non-structural components, namely, plasterboard lining and brick veneer cladding. An extensive testing program was conducted on a full scale one-room-house measuring 2.3m x 2.4m x 2.4m high. This house was tested at various stages of construction to assess the contribution of the various components. Different types of loading, including non-destructive swept sine wave, destructive pseudo-static cyclic racking and simulated earthquakes were employed to obtain the various characteristics of the structure. The testing program on the test house was complemented by further tests on critical components such as brick ties and plasterboard connections. Detailed analytical models were developed and verified against the experimental results. These models were then used to conduct a sensitivity analysis to study other configurations, identify critical parameters and develop design guidelines. The experimental and analytical results have shown that the plasterboard wall lining can provide lateral bracing to domestic wall frames since they effectively act as shear walls. The performance of wall lining is greatly enhanced when set corner joints, ceiling cornices and skirting boards are considered. The capacity is increased by more than three times when these extra components are taken into account. Plasterboard also exhibits high damping and energy absorption capacity which are beneficial under earthquake loading. Furthermore, the strength and stiffness contributions of plasterboard lining and strap cross braces are additive.
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ItemEarthquake design and analysis of tall reinforced concrete chimneys( 2000)Current codes of practice for the design of tall concrete chimneys provide conservative aseismic design guidelines in high seismic regions. A lack of experimental data related to the cyclic behaviour of chimney structures to severe earthquake excitation has resulted in the assumption that such structures are brittle and must be designed in the elastic range. This design approach results in expensive structures and is not consistent with the design philosophy commonly adopted for general structure which permits some inelastic response at the ultimate limit state event. A research program funded by the CICIND organisation has been undertaken to investigate the inelastic cyclic behaviour of tall reinforce concrete chimneys using both experimental and analytical techniques to determine whether the behaviour is brittle or ductile. The research has been divided into three parts; (a) overview of earthquake ground motions, review of the earthquake response of structures and review of chimney design code provisions, (b) detailed description of experimental research examining the cyclic behaviour of chimney sections and (c) development of an aseismic design and analysis procedure for reinforced concrete chimneys including code recommendations. (For complete synopsis open document)
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ItemMaking sustainable develoment ideas operational( 2004)The purpose of the thesis is to develop a General Technique (GT) for use by investigators as a template to help devise investigation programs applying sustainable development ideas (SDIs) to presenting-issues, in order to create ideas for sustainable development actions (SDAs). SDIs are the ‘ideals’, of behaviour for relations amongst people (people-matters) and between people and the environment of the planet (planet-matters) having ancient origins yet being constantly reinterpreted. SDAs are actions that synergistically deliver SDIs in both people-matters and planet-matters concomitantly. The GT was devised in a learning cycle involving theory development and practical experience. The theory of the GT uses a systems-thinking approach to set out the blocks of information necessary to apply SDIs to a presenting issue. The mental model used in the GT is based on the concepts that people are dependent on the planet and that every individual and their actions count. The GT has a Preliminary Step and four Tasks. The Preliminary Step establishes the relationships between the roles of stakeholders and the presenting-issue using a ‘4-group-stakeholder theory’;; group 1 are agents/individuals, groups 2 and 3 are organisations that operate in planet-matters and people-matters respectively, and group 4 are the general public/future generations. Everybody has group 1 and 4 roles and employed people play roles 2 and 3. Task 1 investigates the actions and agents that are fundamental in the presenting issue.Task 2 investigates the agents’; motivations to take up opportunities in both people and planet-matters. Motivations are based on the agents’; desire to satisfy the fundamental human needs (FHNs) of their family. Task 3 investigates: (a) the opportunities in people-matters and planet-matters, using a theory that posits that critical resources and critical arrangements are required for the delivery of FHNs in the very long-term. (b) The involvement stakeholders’; groups have in these opportunities.Task 4 reviews: (a) the success of groups 1 and 4 stakeholders in getting their FHNs met in the long-term and how successful stakeholder groups 3 and 4 are in helping them and why. (b) The maintenance of critical resources compared to the level needed to maintain all life forms and life system on the planet. (For complete abstract open document)