Hosseinzadeh N.,Swinburne University of Technology |
Mayer J.E.,Aurecon Australia Pty Ltd. |
Wolfs P.J.,Curtin University Australia
International Journal of Electrical Power and Energy Systems | Year: 2011
Single Wire Earth Return (SWER) systems are used for supplying electricity at low cost, where electricity supply is required for small populations of people dispersed across wide geographical areas. It is principally used for rural electrification, but is also used for other isolated loads and light rail. The existing SWER distribution systems have been stretched with the sharp growth of their loads because of customers' change of lifestyle, which has introduced additional load of air conditioning equipment, motors driven by variable-speed drives and inverters. This paper proposes cost-effective solutions to address the problem of voltage regulation and compensation of the unbalancing effect of SWER lines on the three-phase feeder of these lines, which have been exacerbated by this load growth. To improve the voltage regulation problem, a LV switchable reactor has been designed, a prototype made and tested in the field. Also, an unbalance compensator has been designed to reduce the unbalancing effect of SWER lines. Two case networks have been used to perform simulation studies on the effectiveness of both proposed solutions. At first, a case study is used to demonstrate the impact of a switchable reactor on improving voltage regulation. Then, another case study shows that installation of a switchable reactor and an unbalance compensator simultaneously on a SWER distribution system effectively improves voltage regulation and reduces unbalancing effects. © 2010 Elsevier Inc. All rights reserved.
Mitchell P.W.,Aurecon Australia Pty Ltd |
Mitchell P.W.,University of Adelaide
Australian Geomechanics Journal | Year: 2013
The problems of the stability of vertical or near vertical excavations in unsaturated fissured clay are discussed. A consideration of the stability of vertical excavations in non-fissured clay, in clay with tension cracks, and by considering the effects of lateral stress relief on excavation in clays without pre-existing fissures, gives greater excavation depths than would be regarded as acceptable in clays. The overall stability of the soil mass containing fissures is governed by the residual shear strength along the joints, particularly with polished slickensides. A common failure mechanism in vertical and near vertical excavations occurs when a slickenside intersects a vertical shrinkage crack. Using the residual shear strength parameters and a planar failure mechanism, the stability of vertical and steeply sided excavations, either supported or unsupported, in fissured clay is discussed. Three case examples are outlined, and recommendations for the successful construction of temporary batters in unsaturated fissured clay are given.
Peterseim J.H.,University of Technology, Sydney |
White S.,University of Technology, Sydney |
Tadros A.,Aurecon Australia Pty Ltd. |
Hellwig U.,ERK Eckrohrkessel GmbH
Renewable Energy | Year: 2013
This assessment aims to identify the most suitable concentrated solar power (CSP) technologies to hybridize with Rankine cycle power plants using conventional fuels, such as gas and coal, as well as non-conventional fuels, namely biomass and waste materials. The results derive from quantitative data, such as literature, industry information and own calculations, as well as qualitative data from an expert workshop. To incorporate the variety of technology criteria, quantitative and qualitative data the Analytical Hierarchy Process (AHP) is used as the multi-criteria decision making (MCDM) tool. Only CSP technologies able to directly or indirectly generate steam are compared in regards to feasibility, risk, environmental impact and Levelised Cost of Electricity (LCOE). Different sub-criteria are chosen to consider the most relevant aspects. The study focuses on the suitability of CSP technologies for hybridisation and results obtained are reality checked by comparison with plants already being built/under construction. The results of this assessment are time dependant and may change with new CSP technologies maturing and prices decreasing in the future.Key findings of this assessment show that Fresnel systems seem to be the best technology for feedwater preheating, cold reheat steam and <450 °C steam boost applications. Parabolic troughs using thermal oil rank second for all CSP integration scenarios with steam temperatures <380 °C. Generally, for steam temperatures above 450 °C the solar towers with direct steam generation score higher than solar towers using molten salt and the big dish technology. At and above 580 °C the big dish is the only alternative to directly provide high pressure steam.In addition to a general CSP technology selection for hybridisation the framework of this study could be used to identify the most suitable CSP technology for a specific CSP hybrid project but this requires detailed information for direct normal irradiance, climate conditions, space constraints etc to provide reliable results. © 2013 Elsevier Ltd.
Suto K.,Terra Australis Geophysica Pty Ltd |
Cenic I.,Aurecon Australia Pty Ltd
74th European Association of Geoscientists and Engineers Conference and Exhibition 2012 Incorporating SPE EUROPEC 2012: Responsibly Securing Natural Resources | Year: 2012
Landfill material is not often documented and its thickness and physical properties are largely unknown. The fill materials from general refuge are commonly known to be loose and its S-wave velocity is lower than the natural ground. However, the fill material can vary and there is no guarantee of such common knowledge to be always true. A Multi-Channel Analysis of Surface Waves (MASW) is a seismic survey method used for near-surface investigation. An MASW survey was applied to a proposed construction site with an uncontrolled fill. The survey covered the car park area with 1729m of seismic data collected in two days with a 24-channel landstreamer. A correlation of the result with the borehole data revealed the fill material has a higher Swave velocity than the natural ground. The MASW method successfully profiled the original ground surface as an interface from high to low Swave velocity. As this sort of velocity inversion is impossible to detect by more commonly used refraction method, the MASW is perhaps the only way to map the original surface under this environment.
Bertenshaw D.R.,ENELEC Ltd |
Smith A.C.,Singapore Institute of Manufacturing Technology |
Ho C.W.,Singapore Institute of Manufacturing Technology |
Chan T.,Aurecon Australia Pty Ltd |
Sasic M.,Iris Power LP
IET Electric Power Applications | Year: 2012
Monitoring the health of large electrical machines, especially power station generators, is now an integral part of their operation to maintain and extend life. This work studies the use of electromagnetic sensors to detect inter-lamination insulation faults in the stator cores of large generators before they propagate to a level that can lead to catastrophic failure. The work develops a deeper understanding of the electromagnetic behaviour of core faults so that condition-monitoring sensors can be more specific about the location and severity of the fault. The study develops two new three-dimensional (3D) analytical models, one for predicting the fault current distribution in a stator core fault and the second for predicting the varying detection of such current by air-cored sensors. This further analysed the 3D detection efficiency of typical short fault lengths to compare with the two dimensional (2D) default of infinite-length faults. Different fault positions were modelled so that a clearer understanding of the location and severity of the fault is possible. These were validated on a specially constructed experimental test core that can impose controlled fault currents. The study also demonstrates how small core faults can escalate then self-limit radially, but may propagate axially into longer more damaging faults. © 2012 © The Institution of Engineering and Technology.
Srivastava H.,Aurecon Australia Pty Ltd. |
Varming C.,Aurecon Australia Pty Ltd. |
Gous W.,Aurecon South Africa Pty Ltd.
20th Australasian Coastal and Ocean Engineering Conference 2011 and the 13th Australasian Port and Harbour Conference 2011, COASTS and PORTS 2011 | Year: 2011
Luderitz Port is the second major port of Namibia. The main berth of the port is a 500m long concrete quay with alongside depth of 8.15m to 4.70m at LAT. The present throughput of the port is about 350,000 tonnes per annum. The main commodities being handled at the port are diesel oil, sulphur, zinc ingot, frozen & wet fish, ice and containers. The port is surrounded by dense population and has very limited area for landside expansion. At present the port doesn't have rail connectivity. A light railway link with a capacity of 1 million tonnes per annum (Mtpa) is under construction which is expected to be completed by 2014. The trade analysis revealed that throughput of the port could be increased substantially, if required equipment, storage and a heavy haul rail linkage is provided. The port has a potential of being developed as a major resource export centre. The throughput of the port could increase to 775,000 tonnes per annum if the port could provide additional equipment, cold storage and container, reefer & break bulk cargo handling facilities. After the light railway is commissioned, the port could get up to 1 Mtpa (limited by railway capacity) of manganese for export. However if a heavy haul railway linkage could be established the port could achieve solid bulk export of up to 50 Mtpa. Considering the trade forecast and limitation of the finances, a three phase expansion plan has been developed for the port. The Phase I and Phase II port development plans are seamless plans, aimed at increasing the utilisation of existing assets at Robert Harbour. In Phase II transhipment facilities for export of manganese in bulk has been introduced as a low cost solution to increase the throughput of the port. In Phase III, major solid bulk material handling facilities are proposed to be built at Angra Point (a new site).
Rohleder R.,Aurecon Australia Pty Ltd |
Stallard H.,Aurecon Australia Pty Ltd
Australian Geomechanics Journal | Year: 2014
An intermodal logistics centre for bulk distribution of shipping containers by both road and rail is currently under construction at a site near Enfield in SW Sydney. The 70 ha project site was used as a rail maintenance facility until the early 1990's, when it was largely dismantled. A container terminal yard will occupy approximately one-third of the project site, which will require construction of a heavy duty pavement to support the operational loads. The design of the terminal area is based on construction of a uniform earthworks platform, requiring both cut and fill to attain design levels, to act as a stable subgrade for the pavement layers. Previous studies revealed the presence of poorly compacted fills across the site that vary significantly both in composition and thickness. Of particular interest was the presence of a significant volume of coal ash fill, which was the thickest fill deposit across a large part of the site. The coal ash was found to be poorly compacted, but laboratory testing indicated it could achieve high strength and CBR index values when compacted to a dense state. The coal ash could thus be treated in place and incorporated into the subgrade earthworks or it could be mined and re-used as general fill in other parts of the site. A programme of field compaction trials was implemented, using conventional vibratory rollers and also impact rollers to determine the optimum compaction method for the coal ash and other fill materials. The field trials showed that compaction of the coal ash significantly reduced its void ratio by approximately 30% with corresponding settlement on compaction. The outcome of these field trials enabled the contractor to develop a ground treatment methodology tailored to the fill material type, which also conformed to the design specification for the subgrade layers.
Turner H.,Aurecon Australia Pty Ltd |
Kerkovius A.,Aurecon Australia Pty Ltd
Long Span Bridges and Roofs - Development, Design and Implementation | Year: 2013
The Seaford Rail Extension Project, recently completed to the south of Adelaide, South Australia, required a 1.125km long viaduct to cross the Onkaparinga Valley and River. The solution chosen was an incrementally launched, concrete box girder, supporting the up and down tracks of the suburban rail line as ballasted track. This paper will consider the design aspects of this structure. The articulation of the structure is highly unusual. Rail/structure interaction on long ballasted deck bridges, as assessed by European guidelines and standards, can result in unacceptable risk of track buckling. An assessment of this complex phenomenon resulted in the partition of the structure into several different sections, each with its own longitudinal restraint system. A series of rail expansion switches and deck movement joints prevent build up of stresses in the rails.
Fowler R.E.,Aurecon Australia Pty Ltd |
Charteris A.,Aurecon Australia Pty Ltd |
Farnes J.,Aurecon Australia Pty Ltd
Coasts and Ports 2013 | Year: 2013
Should management of the coastline be driven by government policy and strategic planning, with nation or state-wide targets for erosion and flood protection? Or should it be driven at a local level, with those people affected by coastal processes determining where money is spent to protect infrastructure and property? This paper explores the approaches used in Australian states and in the UK to manage coastal issues. The opportunities and challenges presented by the different approaches are set out.
Toombes L.,Aurecon Australia Pty Ltd
ISHS 2014 - Hydraulic Structures and Society - Engineering Challenges and Extremes: Proceedings of the 5th IAHR International Symposium on Hydraulic Structures | Year: 2014
Designed by 2007, built by 2010, limits pushed by 2011; the occurrence of an extreme flood event at the Nam Theun 2 hydropower dam system in Laos sparked a reassessment of the hydrology resulting in an increase of over 30% in design flows and leaving the flood release infrastructure well short of the required capacity. This increase and subsequent attempts to re-analyse the release structures, ranging from simplified HEC-RAS modelling to sophisticated CFD and physical modelling, serve as examples of the uncertainty and risks that can be encountered in the design of hydraulic structures.