School of Civil, Environmental and Mining Engineering
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Civil, Environmental and Engineering involves the wise use and conservation of natural resources for the benefit of society.
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School of Civil,
Environmental & Mining Engineering
Ingkarni Wardli Building,
North Terrace Campus
THE UNIVERSITY OF ADELAIDE
SA 5005
AUSTRALIA
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Item Metadata only Lognormal kriging - the general case(Plenum Publishing Corporation, 1982) Dowd, P.A.A theoretical study of the general case of the estimation of regionalized variables with a lognormal distribution is presented. The results of this study are compared to those obtained assuming conservation of lognormality. The numerical significance of the different solutions is illustrated by several simple examples.Item Open Access Aeration for cavitation protection of Uribante Spillway(American Society of Civil Engineers, 1983) Coleman, H.; Simpson, A.; de Garcia, L.; American Society of Civil Engineers, Hydraulics Division Specialty Conference, Frontiers in Hydraulic Engineering (1983 : Cambridge, Massachusetts, USA)Analytical and hydraulic model studies have been made to determine geometry for aeration ramps for Uribante spillway. Two aeration ramps were desi~ned, one at mid-length and one near the flipbucket. Analytical studies were made using finite element analysis of the jet trajectory in order to predict the air demand of the jet. Air supply flowrate was estimated by computation of hydraulic losses in the air supply conduits. The interaction of air demand and supply as functions of jet underpressure allowed prediction of air entrainment. A model study was used to confirm computation of jet trajectory.Item Metadata only Assessing waterlogging controls II: impact formats(American Society of Civil Engineers, 1983) Young, R.; Morel-Seytoux, H.; Simpson, A.; American Society of Civil Engineers Irrigation and Drainage Division Conference (1983 : Jackson, Wyoming, USA)Item Open Access Assessing waterlogging controls I: hydrologic model(American Society of Civil Engineers, 1983) Morel-Seytoux, H.; Simpson, A.; Young, R.; American Society of Civil Engineers Irrigation and Drainage Division Conference (1983 : Jackson, Wyoming, USA)Item Metadata only Problems encountered in modeling vapor column separation(Publisher unknown, 1985) Simpson, A.; Wylie, E.; American Society of Mechanical Engineers Winter Annual Meeting (1985 : Miami Beach, Florida)The discrete vapor cavity model, for describing pipeline transients involving vapor column separation, is based on the method of characteristics with specified time intervals. Vapor cavities are confined to computing sections and a constant acoustic wavespeed is assumed for the liquid. High pressure pulses, which exceed the initial pressure rise due to valve closure, can occur when a cavity collapses.Item Metadata only Geometrical and geological controls in geostatistical estimation and orebody modelling(Society of Mining Engineers Inc/Jostens Publications, 1986) Dowd, P.; The 19th International Symposium on the Application of Computers and Operations Research in the Mineral Industry (APCOM) (14 Apr 1986 - 16 Apr 1986 : Pennsylvania State University, USA); Ramani, R.In practice, many geological controls in automatic or semi-automatic estimation and modelling are essentially geometrical controls. The presents two techniques for geological/geometrical control. Both techniques are types of estimators and/or interpolators of shapes. The first is a method for fitting spline surfaces to control orebody boundary estimation and unroll orebodies. The second is an application of Minkowski addition to interpolate shapes such as orebody outlines or stope boundaries and to control estimations.Item Metadata only Variogram modelling and interpretation: two examples(Leeds University, 1986) Dowd, P.A.Item Metadata only Geostatistical estimation of a section of the Perseverance nickel deposit(D. Reidel Publishing Company (Kluwer), 1987) Dowd, P.A.; Milton, D.W.; Matheron, G.; Armstrong, M.This is a case study illustrating the application of geostatistics to a vein-type nickel deposit. Data are defined in relation to the structural aspects of the geology of the deposit and variograms are calculated for thickness and nickel accumulation. Variogram models are validated by the back estimation technique. A shape preserving spline surface is fitted to the mid-points of drill hole intersections with the orebody and this surface is used to control subsequent estimation. Various drilling densities are evaluated, global reserves are calculated and orebody shape and location are estimated on various horizontal planes. Geostatistical estimates of reserves and orebody shape are compared with the known orebody in a mined area.Item Metadata only Recent advances in the understanding and numerical modelling of column separation in pipelines(Institution of Engineers, Australia, 1987) Simpson, A.; Wylie, E.; Conference on Hydraulics in Civil Engineering (1987 : Melbourne, Australia)The possibility of the coliapse of a vapour cavity generated during column separation in a pipeline during a water hammer event has always been of major concern to designers. A commonly used numerical model for describing water column separation is the discrete vapour cavity model. Studies have shown that the results from this numerical model exhibit numerical spikes of unrealistic pressure rises following the collapse of vapour cavities in pipelines. The cause of these numerical spikes is attributed to the intermittent formation and collapse of vapour cavities at computational sections. The discrete vapour cavity model does not specifically differentiate between localized vapour cavities and distributed vaporous cavitation. This paper considers the importance of the formation of distributed vaporous cavitation zones on the pressure generated by the collapse of a vapour cavity at a valve. An alternative numerical model has been developed that describes water hammer regions, localized vapour cavities and distributed vaporous cavitation regions separately. The formation of intermediate cavities is also accounted for in the model. The implementation of this numerical model is described in this paper. Examples of results from this alternative numerical model and results from the discrete vapour cavity model are compared algainst experimental data collected at The University of Michigan for a 36 meter long pipeline connecting two reservoirs.Item Open Access Numerical modelling of column separation with large pressure pulses(American Society of Civil Engineers, 1987) Simpson, A.; Wylie, E.; American Society of Civil Engineers, National Conference on Hydraulic Engineering (1987 : Williamsburg, Virginia)Liquid transients involving column separation occur in pipelines when the pressure drops to the vapor pressure of the liquid. The collapse of vapor cavities may result in short duration pressure pulses superimposed on water hammer waves, that exceed the Joukowsky or instantaneous valve closure pressure rise. This paper presents the analytical development of an improved mathematical model for describing column separation in pipelines. The model treats distributed vaporous cavitation regions and localized vapor cavities including intermediate cavities. The results from the numerical model are compared with some experimental results for a reservoir-pipeline-valve system.Item Metadata only Column separation experiments with large pressure pulses(ASME, 1987) Simpson, A.; Wylie, E.; Pressure Vessel and Piping Conference (1987 : San Diego, California, USA)Experimental records of examples of distributed cavitation in a pipeline, and of concentrated cavitation at a specific location are presented. The slope of the piezometric level relative to the pipe slope at the time of vaporization controls the type of cavitation. Short duration high amplitude pressure pulses, ie. , times considerably less than 2 L/a seconds in a simple reservoir-pipe-valve system, are shown to occur in cases of localized cavitation, and to be much less apparent in cases in which distributed vaporous cavitation occurs prior to the collapse of the first cavity at the valve. With extensive distributed vaporization along the pipeline the particular short duration pulses of concern are not present.Item Metadata only Towards an improved understanding of water hammer column separation in pipelines(The Institution of Engineers, Australia, 1989) Simpson, A.; Wylie, E.The importance is considered of the formation of distributed vaporous cavitation zones on the pressure generated by the collapse of a vapour cavity at a valve. An alternative numerical model was developed that describes waterhammer regions, localized vapour cavities, and distributed vaporous cavitation regions separately. The formation of intermediate cavities is also accounted for in the model. The implementation of this numerical model is described. Examples of results from this alternative numerical model and results from the discrete vapour cavity model are compared against experimental data collected at The University of Michigan for a 36 meter long pipeline connecting two reservoirs. (A)Item Metadata only Expertise on tap with knowledge based systems(Institution of Engineers, Australia, 1989) Sharpe, R.; Simpson, A.; Prior, M.; First Australasian Conference on Technical Computing in the Water Industry (1st : 1989 : Melbourne, Australia)The paper will describe the development and application of knowledge-based systems (KBS) and expert systems (ES) with emphasis on water engineering both within Australia and overseas.Item Metadata only Expert systems for water treatment plant operations(University of Sydney, 1989) Simpson, A.; Dandy, G.This paper describes the development of two expert systems using the CRYSTAL expert system shell on a personal computer. The first expert system assists an operator in the sequence of actions to be carried out following activation of one of 116 alarms in the control room of the water treatment plant. The second expert system aids a water treatment plant operator in making changes to the alum addition following the activation of one of the alarms related to alum.Item Metadata only Hydraulic model testing of pump sumps(Institution of Engineers, Australia, 1990) Simpson, A.; Harrison, R.; Conference on Hydraulics in Civil Engineering (1990 : Sydney, New South Wales, Australia)The modelling of pump sumps for vortex formation is the focus of this paper. A physical hydraulic model of a large filtered water pumping station at Happy Valley reservoir in southern Adelaide was constructed and tested in 1988. The results and phases of the model test are described. The pumping station has three open sumps. The model scale was 1:10.463. The objective of the model study was to identify and eliminate any vortex formation or excessive swirl in order to maximise the efficiency of pump operation. A parametric study of a number of flow modification elements was carried out. Examples of elements included back splitters, floor splitters, surface beams, screens and fillets. Modifications were also made to the approach chamber leading to the sumps. Eight phases of model testing were performed. The relative effectiveness of various flow modification elements for swirl angle reduction and vortex elimination is summarised. The outcome of the model study was a design that performed satisfactorily with no vortex formation and small swirl angles in each sump. In addition a considerable savings in capital cost was achieved by a significant shortening of the pumping station.Item Metadata only Displacement control and uplift restraint for base-isolated structures(American Society of Civil Engineers, 1990) Griffith, M.C.; Aiken, I.D.; Kelly, J.M.A displacement‐control and uplift‐restraint device that can be installed within multilayer, elastomeric base‐isolation bearings is described. The device acts to limit the displacement of the bearings and is also able to resist tension forces associated with uplift. The device was tested in earthquake simulator tests of a nine‐story, one‐quarter scale steel structure conducted at the Earthquake Simulator Laboratory of the Earthquake Engineering Research Center of the University of California, Berkeley. The test structure was isolated using eight multilayer, elastomeric bearings, four of which were located at the corners of the structure and contained the restraint devices. The system was subjected to a large number of simulated earthquakes. In some tests the devices acted to control the displacements, and in others, where uplift forces were generated, the devices simultaneously limited the displacements and carried the uplift forces. The test results show that the action of the devices is smooth and that there is no sudden jerk when one comes into action. The devices can perform as a fail‐safe system for base‐isolated buildings. In this role they would be designed to act only when the ground motion is greater than that for which the base‐isolation system has been designed.Item Metadata only Water hammer analysis of pumping systems for control of water in underground mines(International Mine Water Association, 1991) Bergant, A.; Simpson, A.; Sijamhodzic, E.; International Mine Water Association Congress (4th : 1991 : Ljubljana, Slovenia, Austria); Norton, P.J.; Veselič,, M.This paper considers water hammer analysis of pumping systems for control of water in underground mines. The basic mechanisms causing water hammer events in pipe systems are introduced. Expressions for the wave speed in both an infinite fluid and in a thin-walled pipeline is presented. The equations of unsteady flow in pipelines and the method of characteristics solution to these equations are described. Methods for controlling water hammer in pipelines are described. Two boundary conditions are discussed including the reservoir and the pump. A case study for a pumping system in an underground mine in Velenje, Yugoslavia is presented in detail. Field measurements are compared with a computer simulation analysis of a transient during power failure to the pump. The results show that the method of characteristics is an acceptable method for water hammer analysis of mine pumping systems.Item Metadata only Column separation research at The University of Adelaide, South Australia(Universidad Politecnica de Valencia, Fluid Mechanics Group, 1991) Simpson, A.; Bergant, A.; International Meeting on Hydraulic Transients with Water Column Separation (9th : 1991 : Valencia, Spain)Item Metadata only Minimum weight structures designed by genetic algorithms(A. A. Balkema, 1991) Sved, G.; Schmid, L.; Simpson, A.; Asian Pacific Conference on Computational Mechanics (1991 : Hong Kong); CHEUNG, Y.K.; LEE, J.H.W.; LEUNG, A.Y.T.The weight of a fully stressed structure with a prescribed geometry, carrying a single or multiple loading, can be altered by "prestressing", making one or more members too long or too short. In this paper a Genetic Algorithm is used to calculate the optimum prestressing. Finally, it is shown that the structure will "shake down" to this optimum if the "zero load" case is included in the calculations, even if the actual structure is manufactured without prestressing.Item Open Access Large water-hammer pressure for column separation in pipelines(American Society of Civil Engineers, 1991) Simpson, A.; Wylie, E.Water-hammer pressures in a pipeline due to the collapse of a vapor cavity adjacent to a valve are investigated. A water-hammer event is initiated by the closure of a valve in a simple reservoir-pipeline-valve system. The sequence of events following an instantaneous valve closure leading to the formation and collapse of a vapor cavity and the resultant occurrence of a short-duration pressure pulse are described. Short-duration pressure pulses result from the superposition of the valve-closure water-hammer wave and the wave generated by the collapse of the vapor cavity. The resulting maximum pressure may exceed the Joukowsky pressure generated from the initial valve closure. A series of numerical model analyses exhibiting short-duration pressure pulses are presented. In addition, experimental results supporting the findings of the numerical studies are also presented. Experimental plots of hydraulic grade line versus time exhibit short-duration pressure pulses of different shape and characteristics.