Infrastructure Engineering - Theses
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ItemA new refined approach to the formulation of the earthquake-resistant design regulations for torsionally coupled multistorey buildings( 1989)This thesis presents a detailed parametric study of the elastic earthquake response of torsionally coupled single and multi storey buildings using a probabilistic approach. The aim is to validate the findings of previous deterministic studies, to assess the empirical design procedures stipulated by the current provisions of building codes, and to critically appraise the alternative design recommendations made by the earlier deterministic studies. The structural models are idealised by a discrete parameter prismatic shear beam model which is representative of low to moderately high rise frame-type buildings. The earthquake horizontal ground motion is modeled as a Gaussian, zero mean, stationary random process that is fully characterised by a probabilistic ground acceleration power spectrum. The first and second order statistical parameters defining such a spectrum are derived from an ensemble of 68 actual earthquake motions recorded in the west coast of the U.S.A. A new procedure called the Intensity Correlated Probabilistic Power Spectrum Method (ICPPSM) is developed. This procedure uses the standard random vibration and extreme value theories, and the new concept of the intensity correlated probabilistic power spectrum to compute the mean peak structural responses. Based on the numerical results obtained from the probabilistic approach, a more rational three-step formulation to the codified seismic torsional provisions is proposed to allow for the coupling effects in the design of multi storey buildings.
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ItemNon-current data and land information systems( 1986)Within the larger Land Information Systems (LIS) being developed in this is likely that several thousand records per day will be and thus become non-current. In order to minimise system country, it superceded, operating costs, the logical solution is to delete these data when they cease to be current, however this ignores any present or future value which they might have to other users. The purpose of this thesis is to examine the problems of non-current data produced in a LIS, such as: identifying the users; the law affecting records disposal; deciding which data are worthy of preservation; storage methods; costs and benefits; and the present policies being adopted by organisations establishing LIS, with respect to this subject. In addition, the practical aspects of archiving superceded graphical data were investigated during development of an historical Digital Cadastral Data Base - a system capable of displaying the parcellation of a region at any point in time since first settled.
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ItemSimulation of hay-making systems( 1986)In southern Australia, fodder is conserved mainly as hay, and pasture is the common raw material. This hay-making process is complex and, unlike other harvesting operations which are virtually instantaneous, involves a series of sequential operations with three or more different machines. It also involves a number of major and minor management decisions in a highly variable weather regime and with continuously changing crop conditions. A simulation model has been developed to evaluate alternative hay-making systems and management policies in terms of the digestible dry matter (DDM) yield of hay and of the harvesting time. The main simulation is based on a series of sub-models associated with pasture growth, weather forecasts, management, hay-drying and hay losses. Some of these models are based on the available literature and others have been developed by the author. Field-drying experiments with unconditioned and conditioned pasture were conducted to develop the hay drying model which also includes the effect of dew and rain. A method was developed to make an assessment of three-day weather forecasts for scheduling hay-making operations. Simulation experiments were carried out by using 16 years of historical weather data from Laverton, Victoria. Management factors such as weather prospects after cutting, maximum cut crop allowed in the swath and maturity at the start of season were found to affect the DDM yield and harvesting time. To achieve a significant increase in DDM yield of hay, either an improvement in the accuracy of weather forecasting is necessary or the drying time in the field must be reduced by applying a treatment such as conditioning of the crop at the time of cutting. The major limitation of the present simulation model is the lack of data. Research is needed to refine the loss parameters due to environmental factors and mechanical operations on which the DDM yield is based. A number of other promising research areas also are outlined to extend the use of the present model and make improvements to it.