2006 Seminar Series
Abstracts
Seminars |
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Date |
Presenter |
Topic |
| 30 Oct | Juan Jofre | This research has been performed on a particular granular material, Hydraulic Backfill (HF), but the recommended testing procedure is applicable to other particulates. During the investigation, several sources of errors were identified and rectified on what appears to be a simple laboratory test, resulting in an innovative methodology which is complementary to current standards. HF is widely used to fill cavities left by ore extraction in underground mines. The backfill is pumped in as high density slurry and excess transport water must drain out of the stope during and after placement. Poor design and poor operation of the drainage have ended in serious accidents which, in the worst cases, have been fatal. Our Department was part of a team analysing one of these accidents and its participation led to a request from Backfill consultants to perform an investigation on the topic. Consequently, this study, ‘Backfill Lower Boundary Permeability Prediction’, started. Currently, based on the methodology recommended by this research, the following is possible:
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| 23 Sept | Amgad Elmahdi | In Australia, one of the crucial water resources management problems is allocating water among conflicting uses more efficient and equitable, and adequately protecting the river health. In the Murrumbidgee river basin, irrigation extraction, water institutional and land clearing have had major impacts on the river environment and water allocation. Irrigation demand has changed the natural flow regime of the river in terms of volume and time which have induced significant environmental changes. These problems are compounded by extreme climatic variability and potential climate change. Therefore, this research aims to help develop understanding of how to improve the seasonal flows and the environmental quality of Murrumbidgee River through investigates a range of possible proposed demand management options.
Finding ways to meet irrigation demands and also achieve positive environmental and economic outcomes requires innovative policy initiatives. However, given the complexity of river questions, modelling tools are required to analyze the impact of alternative demand, allocation and policy scenarios. This could be achieved by linking irrigation demand and conjunctive water use management with water banking approach to improve the management of surface and groundwater resources in irrigated catchments but also to satisfy the environmental flow requirement. Under this research, an integrated hydrological economic dynamic model has developed (using system dynamics) and used to measure and identify the change in economic output and environmental impacts of various allocations and demand from irrigation on improved seasonality of flows and environmental flow target. |
| 16 Nov | Prof Marcus Wigan | The European Commission Framework Series of research programs are large projects (usually 3 to 10 million Euros) and involve many countries. The 6.4M Euro ReOrient project is investigating barriers to EU railway integration and involves US, UK, Norwegian, Dutch, German, Finnish and other countries. This presentation describes and illustrates the distributed document, data, spatial analysis, communication systems built into a simple web interface (www.reorient.org.uk) and will illustrate the way in which very large freight and transport databases can be made accessible in a usable archive by illustrating the huge EU ETIS freight database which has been loaded into the KB, while supporting an active project. The integrated use of video conferencing, WIKIs and other tools for distributed management will be shown - and the successes and failures discussed... there has been substantial interest in the EU and major railway organisations to adopt this KB system and extend it after the project is finished. The new requirements on UK Universities to develop repositories for documents and research and knowledge transfer are also met by this KB. |
| 9 Nov | Keith Smettem | The soil surface is the earth-atmosphere interface in terrestrial systems and the critical zone for sustainable management of the soil and water resource base across the planet. Infiltration is one exchange process of particular hydrologic significance in the critical zone. This is the passage of water across this air-earth interface and is influenced by both climatic and surface conditions. Most physically-based distributed numerical catchment hydrologic models usually assume the porous media to be rigid, with fixed properties through time. Soil mapping also emphasizes 'fixed' properties, so the coupling of soil spatial databases with infiltration and water balance models reinforces this paradigm. In this seminar I start by discussing the problems of scale and parameterization in distributed hydrologic modeling of infiltration and runoff. I then propose that infiltration theory provides an avenue for parameter reduction and can be used as a convenient tool for mapping surface soil hydrologic response to rainfall and for initial delineation of hydrologic response units in upscaled hydrologic models. Onto this basic template I then consider the questions: how do soil crusting and non-wetting behaviour affect the process of infiltration and our ability to characterize it? Furthermore, how widespread are these processes and can we map their occurrence? I provide examples to show that in some cases, our current measurement techniques and concepts are misleading and that a new attack on the problem of infiltration in spatially and temporally dynamic systems is long overdue. |
| 2 Nov | Prof Ray Ison | Drawing on SLIM Project research (see www. slim.open.ac.uk ) the seminar will address the application of social learning as a conceptual framework, an operational principle, a policy instrument and a process of systemic change in relation to water and catchment managing. A premise of SLIM is that it is very useful to view sustainability as an emergent property of stakeholder interaction, and not the technical property of the ecosystem. Ray will also draw on recent research within the English Environment Agency concerned with implementation of the European Water Framework Directive. |
| 26 Oct | David Heath | Blasting is employed in quarries and mines throughout Australia to fracture rock. Some homeowners in nearby residential areas become alarmed when they experience blast vibrations and often believe damage such as cracking in their house is vibration induced. This issue has necessitated research into the performance of non-structural components in houses including masonry veneer. Research in this project focuses on the onset and development of cosmetic cracking and ultimately seeks to identify levels of vibration responsible for causing damage. A number of static tests have been carried out on specimens to investigate the performance of unreinforced masonry to in-plane loading. The final test of this series is a shake-table test of a full scale single room house having construction representative of a typical domestic brick veneer structure. This test investigates the performance of masonry veneer containing penetrations to ground vibrations. Initial tests conducted have confirmed the dynamic characteristics of the specimen are representative of a typical house. The second phase of testing is due to commence shortly and shall include shaking the specimen to increasing levels of simulated ground vibrations. |
| 19 Oct | Haider Al Abadi | Abstract: As demonstrated by major earthquake events in recent years, damage to non-structural components and building contents (BC) have been major contributors to casualties, business disruptions and economical losses. In recent years, building codes have begun to address potential damage to BC, but this has been handicapped by the lack of knowledge on their potential behaviour in an extreme event. Current building codes adopted the general assumption that “BC are fully restrained from movement” while field investigations for evaluating the installation details of BC reveals that current building codes assumption is unrealistic, since most critical BC are typically free from fixation. Accordingly, the general question of this research project is: “Is it required to restrain all BC?”. The main objective of the above titled research project is to evaluate the response of the floor mounted BC (e.g. computer storage racks, cabinets, and boilers) to the excitation of their supporting floor due to seismic activity. This evaluation includes investigation on two main points which are: (1) overturning risk assessment of BC due to floor excitation and (2) impact shocks development onto BC during rocking response. |
| 12 Oct | Dr Robert Argent | The eWater CRC has an extensive research program for total water cycle management in urban and rural catchments, including water quality and quantity, stream ecology and economics considerations. Early developments are occurring in the water quantity, water quality and stream ecology areas, requiring development of a conceptual approach that is shared. This seminar will present a common conceptual model of how constituents are generated, move through the landscape, and are transported and transformed. |
| 28 Sept | Thanh Binh Ta | The main aim of this research is to conduct an experimental and theoretical investigation on the behaviour of high strength concrete (HSC) structures (walls and columns) subjected to evaluated temperatures. The spalling of HSC members subjected to hydrocarbon fires will also be investigated. The research involved the tests of concrete walls and columns subjected to both standard fires and hydrocarbon fires. Three types of concrete: normal strength concrete (NSC), HSC with and without polypropylene fibers will be tested. The numerical modelling of the concrete members using FE code has been carried out to predict the behavior of three-dimensional reinforced concrete structures subjected to high temperatures. Theoretical results will be compared with the fire test results. |
| 14 Sept | Dr Brent Davey | The Australian Alternative Cover Assessment Project (A-ACAP) is a major environmental engineering initiative, aimed at demonstrating the suitability of “alternative” covers, particularly phytocovers, for landfills under Australian conditions. Currently, landfills in Australia are closed using highly engineered low-permeability structures involving compacted clay, and often including geomembrane layers. These covers are expensive, yet they frequently fail, allowing water to penetrate to the buried waste, creating potentially hazardous leachate, and allowing odours and greenhouse gases to escape to the atmosphere. “Alternative” covers, such as ET or evapotranspiration covers and phytocaps, address the issue of landfill closure with a different approach, by harnessing water balance principles to minimise infiltration of water into the underlying waste. This approach has been pioneered by the Alternative Cover Assessment Program in the United States, and A-ACAP is intended to extend it further, by deliberately including plants in the cover. The plant component contributes to the efficiency of the cover by enhancing evapotranspiration, and by providing in the root zone an environment for microbial activity that can bring about significant reductions in odours and greenhouse gas emissions. Led by Dr Sam Yuen in collaboration with Prof Alan Baker of Botany and investigators from five other Australian Universities, in partnership with the regulators and industry (represented by the Waste Management Industry Association of Australia), this project is supported by one of the largest ARC Linkage Grants in 2005. Ultimately, it will provide guidance to the waste management industry and its regulators on better ways of capping landfills throughout Australia. This seminar will provide an overview of the project’s structure and aims, explore its research questions, experimental approach and data objectives, and provide a brief insight into progress with alternative cover research in Australia and overseas. |
| 07 Sept | Keven Ellet | Launched in 2002, the twin satellites of the Gravity Recovery and Climate Experiment (GRACE) provide unprecedented accuracy in the retrieval of the earth’s gravity field whose variability arises from the broad-scale exchange of water mass between the land, atmosphere and oceans. Early studies have demonstrated the effectiveness of this novel observation in sensing the global-scale variability in terrestrial water storage and other significant phenomena such as the accelerated melting of the Greenland ice sheet. The ability of GRACE to provide a useful new contribution in regional-scale hydrology was uncertain, however, owing to the integrated nature of the observation (i.e., the summation of all water mass including soil moisture, ground water and snow/ice) and the extremely course spatial (~ 106 km2) and temporal (monthly-mean storage) resolution of the observation. The objective of this thesis is to explore the potential utility of GRACE in the analysis of hydrological processes at the catchment-to-basin scale. Following an overview of the GRACE mission and research methodology I will present results from analyses using hydrological modelling, data assimilation and in-situ monitoring in the Murray-Darling Basin which demonstrate the usefulness of this unique new observation. The presentation will focus on the 3 original contributions that the thesis aims to achieve: (1) providing the critical first validation of terrestrial water storage observations from GRACE based on in-situ measurements, (2) demonstrating the potential of GRACE to improve hydrological model prediction at the catchment scale (104 – 105 km2) through data assimilation techniques and (3) evaluating the performance of various model parameterisation schemes in simulating hydrological processes across the whole of the Murray-Darling Basin. Beyond the positive results there are also some important limitations of GRACE that are identified in this work. These limitations will be discussed along with the direction of future research and the prospects that may arise from a proposed follow-on mission to GRACE. |
| 31 Aug | Adam Smith | Gravity observations have the potential to provide an exciting new source of remotely sensed data to constrain the water balance in land surface models. This would result in more accurate soil moisture and flux predictions and correspondingly improved numerical weather prediction and global climate forecasts. However before dedicated gravity satellites (e.g. GRACE) can be utilised in an operational setting it must be shown that a soil moisture signal is detectable in gravity observations. This is extremely difficult to show directly for satellite observations due to the massive spatial scale involved (1000 square kilometres or larger). Therefore a ground-based field study of soil moisture, groundwater and gravity changes is essential in verifying the magnitude of the hydrological signal in gravity observations. Results are presented from two field sites in the Kyeamba Creek catchment in NSW where soil moisture, groundwater and gravity have been monitored for one year. One is a hillslope site with no groundwater whereas the other is a valley site with a shallow water table. From autumn to spring 2005 the valley site is found to have a significant change in gravity that corresponds extremely well to the predicted hydrologically induced change. |
| 24 Aug | Wirtu Bayissa | Structural damage may occur due to long-term deterioration under service load or after a structure is exposed to extreme loading events such as earthquakes and impact loads. Damage causes changes in the structural physical properties, mainly stiffness and damping, which alter structural response behavior and affect current and future performances. Consequently, monitoring of global structural condition becomes critical for identifying the early onset of damage thereby preventing damage-induced collapse and to maintain structural integrity, performance and safety. In the past, techniques based on vibration response measurements have been used for damage identification and health monitoring in the areas of aerospace, automotive, civil and mechanical engineering. This study presents a two-stage, vibration-based non-destructive evaluation technique for structural damage identification and condition assessment. First, “damage-sensitive” vibration response parameters that have strong physical dependence on structural dynamic properties are identified using time-domain, frequency-domain, spectral-domain and wavelet-domain analysis and “non-model” based damage identification approaches. “Model-based” damage identification methods are then proposed in the context of global optimization and Bayesian probabilistic methods for detection, localization and estimation of damage severity. The results show that the proposed damage parameters performed remarkably well as compared to existing, well-established alternatives. |
| 17 Aug | Dr Luis Neumann | Suspended sediment in most estuaries is found in the form of aggregates and is closely related to turbidity. Turbidity is not only related to the concentration of sediment, but also to the particle size distribution of the sediments, as small particles diffract more light than large ones. The particle size distribution of the flocs is constantly changing under the influence of the flow conditions through flocculation and breakage. A set of flocculation experiments was performed using sediments from the Brisbane River, Australia. The sediments were flocculated in a Couette device to evaluate the influence of shear and salinity on the flocculation efficiency and the breakage rates. Particle size dynamics were modelled using population balances with flexible grids to overcome limitation of the fixed grid methods common in most flocculation studies. The population balance model and the settling velocity information were used to solve a model of the advection diffusion equation coupled with flocculation and breakage. This model was used to simulate the behaviour of sediments during the slack tide in the Brisbane River. The model could track the changes in the concentration profile and particle size distribution through most of the water column. It is demonstrated that the results are highly dependent to the vertical diffusion and settling velocity description. It is also shown that the number of equations in the population balance can be reduced to gain computational efficiency while still achieving good results. |
| 10 August | Assoc Prof Priyan Mendis | The ARC Research Network for a Secure Australia (RNSA) is a multi-disciplinary collaboration established to strengthen Australia's research capacity for protecting critical infrastructure from natural or human-caused disasters. The RNSA will facilitate a knowledge-sharing network for research organisations, government and the private sector to develop research tools and methods to mitigate emerging safety and security issues relating to critical infrastructure. A general overview of the ARC research network scheme will be presented followed by a brief summary of the activities of RNSA. This network is co-ordinated by the Department and there may be opportunities to participate. The recent projects of RNSA include the SET (Science, Engineering and Technology) Summit in September and a joint study with Academy of Science on the effect of climatic change on physical infrastructure in Australia APTES/RNSA co-ordinated an industry group from Australia to participate in explosion tests in Woomera in April/May 2006. Finally an overview of these tests and other related research in this area will be presented. |
| 08 June | Dr Justin Costelloe | A land of droughts and flooding rains". This often used quote is particularly apt for the Lake Eyre Basin of central Australia. The Basin contains Australia's driest regions, including the Simpson Desert, but also contains large, iconic river systems, such as the Diamantina River and Cooper Creek, that drain into Lake Eyre. During drought periods these rivers contract into widely separated waterholes whilst during flood events, the inundated floodplain can be up to 50 km wide. The ecological responses to these radically varying hydrological conditions are equally as spectacular. Flood events result in booms in plant and animal populations and can bring millions of waterbirds into the Basin. While in drought conditions, the aquatic animals retreat to the few remaining waterholes or develop drought-resistant stages. This talk will summarise the findings of the ARIDFLO project, that studied ecological responses to hydrological events during the period 2000-2003 in the Lake Eyre Basin. |
| 01 June | Dr Jeffrey Walker | The National Airborne Field Experiments (NAFE) are a series of intensive campaigns being conducted in different parts of Australia to answer a range of open questions in relation to soil moisture mapping from the ESA Soil Moisture and Ocean Salinity (SMOS) mission. While the objective of the NAFE’05 experiment was to provide high resolution data for process level understanding, the objective of the NAFE’06 experiment is to provide data for SMOS level soil moisture retrieval, downscaling and data assimilation. The primary instruments flown during these campaigns are the Polarimetric L-band Multibeam Radiometer (PLMR) and supporting instruments (thermal infrared radiometer, tri-spectral scanner, digital camera and lidar), providing passive microwave data from 50m to 1000m resolution coincident with optical data from 1m to 20m resolution and groundbased soil moisture measurements at 6.25 to 1km resolution. This seminar will review the data collected during the NAFE’05 campaign and its current state of processing, and preview the plans for the NAFE’06 campaign. The NAFE’06 campaign will be undertaken in the Murrumbidgee catchment during November 2006. While this experiment has a particular emphasis on the remote sensing of soil moisture, it is open for collaboration from interested scientists from all disciplines of environmental remote sensing and its application. See www.nafe.unimelb.edu.au for more detailed information on these experiments. |