Thiess Pty Ltd

Woori Yallock, Australia

Thiess Pty Ltd

Woori Yallock, Australia

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Arulrajah A.,Swinburne University of Technology | Abdullah A.,Affendi and Partners Consult | Bo M.W.,DST Consulting Engineers Inc. | Leong M.,Thiess Pty Ltd
Proceedings of the Institution of Civil Engineers: Ground Improvement | Year: 2015

A high-speed railway project for trains with speeds of 160–180 km/h was recently completed in Malaysia. An array of geosynthetics such as biaxial geogrids, non-woven geotextiles and woven geotextiles were extensively used in the project primarily for separation, filtration and reinforcement purposes. The geosynthetics were particularly used at locations of high embankments underlain by soft clays and loose sands. Ground improvement using geosynthetics in the project primarily included geogrid-reinforced piled embankments with individual pile caps, geogrids at bridge approach transitions, geogrids for ground treatment beneath culverts, geogrids for culverts supported by stone columns, woven geotextiles for cement column works, non-woven geotextiles for excavation works, non-woven geotextiles at the top of the railway subgrade layer, non-woven geotextiles for temporary retaining walls and nonwoven geotextiles for slope protection works. This paper provides a detailed insight into the design and implementation of ground improvement using geogrids and geotextiles in this case study project, with a focus on the geogrid reinforcement design of piled embankments with individual pile caps. The use of geosynthetics in the various railway applications in the project was found to provide safe and cost-effective solutions to the various geotechnical engineering challenges encountered. © ICE Publishing: All rights reserved.


Ozbey N.,Thiess Pty Ltd
Proceedings of the 34th Hydrology and Water Resources Symposium, HWRS 2012 | Year: 2012

Since velocity and water height in a river vary drastically with time during a course of an extreme flood event, obtaining an accurate discharge measurement may not be possible. A method which requires quick velocity sampling on a vertical axis may be more appropriate to deploy in such flow conditions. Chiu derived a velocity distribution equation utilising probability concepts by maximizing the Shannon's probability-based information entropy. He showed that the probability law is capable of formulating vertical and horizontal velocity distributions both at an irregular section in a river and a defined section of a channel by relating maximum velocity, 'u max ', occurring on or below the water surface to a cross sectional mean velocity, 'u'. The equation corresponding to an exponential probability distribution has a single parameter called the Entropy Parameter, 'M'. By using the equation with the dimensionless cumulative distribution function, 'î', with which 'u' develops, the velocity-distribution parameters 'umax ', 'M', and location of maximum velocity, 'h' are determined from the vertical velocity profiles. The 'M' value is then used to define the ratio of 'u' to 'u max ' which remain constant with height at a section but varies from section to section with roughness and geometrical shape of a section. The method is applicable to both the steady and unsteady flows. THIESS uses the methods recommended by relevant Australian Standards when undertaking discharge measurements. Cross section is divided into more than 20 sections to approximate the cross sectional area and the velocities are sampled at two or three points at each vertical, at 0.8, 0.6 and 0.2 of a depth below water surface respectively to estimate mean velocity of a section. Utilising Chiu's approach, the relationship between the maximum velocities measured, generally at 0.2 of a depth below water surface, and the cross sectional mean velocities of the measurements are sought by examining the discharge measurements undertaken at 50 stream gauging sites with different hydraulic characteristics and geometrical shapes over the past 40 to 50 years. The sites are located on the Murray, Wimmera, Werribee, Kiewa, Ovens, Mitta Mitta and Goulburn Rivers and rivers in Gippsland and other mountain rivers of Victoria. It is found that the value of a constant, 'β1 ', for each site remains constant with the stage and varies from site to site.


Ozbey N.,Thiess Pty Ltd
Proceedings of the 34th Hydrology and Water Resources Symposium, HWRS 2012 | Year: 2012

Precision of hydraulic-models approximating hydraulic behaviour of a flood rely on accuracy of calibration process. In the absence of reliable hydrologic data, poor assessment in assigning hydrological parameters such as Manning Roughness-coefficient, 'n', may lead to substantial uncertainty in peak discharge estimation since the value of 'n' is difficult to determine when spatial and temporal variation is significant. In practical applications, the universal logarithmic-law has been utilised to estimate 'boundary shear velocity', 'u', and 'Nikuradse's equivalent sand-roughness', 'k s', which is based on the assumption that the law is valid over the whole depth of open channel flow. Keulegan established the relationship between 'n' and hydraulic-radius, 'R', and ' k s'. Chen proposed a generalized power-law model for vertical-velocity distribution in open channels. According to this model, mean velocity in wide open channels based on the power law with exponents 'm', is equivalent to Manning's equation hence 'n' can be related to 'ks' and 'R'. By deploying an Acoustic-Doppler Current Profiler and using Stationary-Method (ADCP-SM), the vertical velocities of sections through the rivers were profiled. The accuracy of SonTek M9 was tested several times at the sites, including pre-calibrated measuring structures where the rating tables were reliable and developed using different measuring techniques. Utilising the power-resistance formulas and the log-laws for fully rough flows, the parameters, 'u', 'ks' and 'n' were estimated for each section consequently for the entire cross sections with discharge-weighted method. Estimated 'n' and the energy gradient slopes derived from the measurements were adopted to determine the conveyances and subsequently the peak discharges experienced at the stream gauging sites in Victoria during 2011 Floods. Finally the method in ISO 5168 is adopted to estimate the uncertainties in calculated values of Manning Roughness, 'n'. © 2012 Engineers Australia.


Liu Y.,Parsons Brinckerhoff | Munro J.,Parsons Brinckerhoff | Dandie B.,Thiess Pty Ltd
International Journal of Ventilation | Year: 2010

Emergency smoke ventilation for a uni-directional traffic road tunnel is studied using a CFD modelling approach. Fire scenarios in an uphill ramp for congested traffic conditions have been considered. Based on a longitudinal smoke ventilation system with a damper smoke-extraction device on the ceiling soffit, the impact of longitudinal ventilation (LV) control, operation of fire suppression intervention and emergency response delay have been quantitatively investigated. An assessment conducted with CFD modelling quantitatively shows to what extent the visibility is influenced. It has been revealed that longitudinal airflow velocities can influence the performance of damper smoke-extraction. Different longitudinal airflow velocity should be maintained for fires in different tunnel locations under congested traffic conditions. This is important for tunnels with a fire suppression system, as smoke flows to the lower location when hot layer stratification is disturbed by the application of water. Fire suppression can cool down the smoke temperature significantly, but the visibility in the downstream portion of the tunnel can be impacted if longitudinal ventilation is not properly controlled For the modelled conditions with a heavy goods vehicle (HGV) fire in a 5% uphill ramp section of a tunnel, an LV flow velocity of 2 m/s can maintain tenable conditions upstream and downstream for congested traffic conditions.


Pippenger J.G.,Thiess Pty Ltd.
Mining Engineering | Year: 2011

Rio Tinto Coal Australia built the Meandu Mine in 1983 expecting to deliver 25 years of cost effective energy to the Tarong Power Station, never expecting the massive changes that would impact those next 25 years and beyond. RTCA eventually lost faith in Meandu's ability to continue providing long-term profitable coal, thus the decision to close Meandu and move to Kunioon beyond 2010. It took a change in ownership and fresh eyes to see that Meandu was not the washed-up has-been mine previously believed. Two years of studies, numerous changes in equipment and mining concepts, tens of kilometers of additional exploratory drilling and myriads of mine plans finally allowed Meandu to rise from the dead and continue providing low-cost energy to the Tarong Power Station for at least the next 15 years. It just goes to show that no mine is really dead until a mining engineer says it's dead.


Waller A.,Thiess Pty Ltd | Vimonsatit V.,Curtin University Australia
Australian Journal of Civil Engineering | Year: 2012

Australian built environment is constantly expanding and a review of the methods and guidelines used to assess existing structures is required to ensure the safety of the structure and its occupants. This paper reviews the current Australian guideline for the assessment of an existing structure (AS ISO 13822) and compares it to the guideline used in the United States of America. The analysis of the Australian guideline yielded three possible areas of improvement. A hypothesis on the introduction of building licence was set which would account for and improve these areas. A case study was carried out with the Thai Building Control Act, B.E 2522, Section 32. This Act outlined the introduction of compulsory structural assessments. Interviews with key professional members in the assessment industry were conducted to seek industrial opinions on the regulated assessment initiation and changes that would need to be made for a successful implementation. © 2012 Institution of Engineers Australia.


Pippenger J.G.,Thiess Pty Ltd.
SME Annual Meeting and Exhibit and CMA 113th National Western Mining Conference 2011 | Year: 2011

In all this report, I have left out the best part of being in Australia: the people. I have the pleasure to work and live with some of the most genuine wonderful people I have ever known, even if I do get my share of ribbing for being American and not knowing how to speak proper Aussie (its al-u-min-i-um not a-lum-in-um). One thing I have learned about Aussies, they are not afraid to have a good time and that includes "having a go" (poking fun) at others or themselves. Just catch Question Time at 3 PM every day when Parliament is in session. I guarantee you that no comedy act can touch the jibs and jibes that the political parties fire at each other in that hour of national television, something you would not see on CSPAN in a million years. And yet it is all just good Aussie fun. I have lived in both remote and urban locations over the past 10 years and have found both to be wonderful, although my present home in Kingaroy offers the best of both worlds. At the same time, I have found a career in the Australian mining industry that is both rewarding and challenging allowing me to earn the respect of colleagues, make valued contributions to my company and gain the financial and personal surety that comes from knowing you are at your best. So come on over for a visit, go walkabout (tour the country) and you too just might find yourself staying for a whole lot longer than you planned. We'll be sure and pull out the barbie (BBQ grill of course) and throw on some snags (sausages) and rissoles (kind of like hamburger). No we won't have "shrimp on the barbie" as Paul Hogan once offered in American commercials. That was a term created for US television. Americans eat shrimp; Aussies have prawns. Anyway, if you are up for a new challenge, new adventures or just looking for a change of pace, I can heartily recommend a tour of duty in Australia. Mining is booming, the salaries are great, there are more jobs than you could physically apply for and the lifestyle can be as simple or adventurous as you desire. And I have not even touched on the strange incredible wildlife. For example, only Australia has the duckbill platypus, the creature God made out of spare parts. In summary, Australia is a wonderfully unique and fascinating land filled with the most interesting and beautiful people. I ought to know, I married one.


Pippenger J.G.,Thiess Pty Ltd.
SME Annual Meeting and Exhibit and CMA 113th National Western Mining Conference 2011 | Year: 2011

Rio Tirito Coal Australia built the Meandu Mine in 1983 expecting to deliver 25 years of cost effective energy to the Tarong Power Station, never expecting the massive changes that would impact those next 25 years and beyond. RTCA eventually lost faith in Meandu's ability to continue providing long term profitable coal, thus the decision to close Meandu and move to Kunioon beyond 2010. It took a change in ownership and fresh eyes to see that Meandu was not the washed-up has-been mine previously believed. Two years of studies, numerous changes in equipment and mining concepts, tens of kilometres of additional exploratory drilling and myriads of mine plans finally allowed Meandu to rise from the dead and continue providing low cost energy to the Tarong Power Station for at least the next 15 years. It just goes to show that no mine is really dead until a mining engineer says it's dead.

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