Tanaz Dhondy wins international award

Costin Roe Consulting design engineer and PhD candidate, Tanaz Dhondy, received an award for ‘Best Oral Presentation’ following the delivery of her preliminary research findings at the inaugural International Workshop on Coastal Reservoirs held in January 2018, at the University of Wollongong.

Tanaz Dhondy wins international award

Tanaz Dhondy received the oral presentation (research) award at the IACRR Workshop 2018.

Titled: Investigation of the chemical and physical properties of sea sand for the possible use in concrete for coastal infrastructure, Tanaz’s award-winning presentation summarised the preliminary findings of Stage 1 of her PhD research.

Tanaz described the invitation to speak at the International Workshop on Coastal Reservoirs as “an amazing opportunity”, and receiving the award for ‘Best Oral Presentation’ at the event “an honour”.

“Around the world, cities appear to be running out of water. But is it the water that is running out of the cities?” – IACRR

Tanaz Dhondy speaks at the IACRR Workshop 2018.

Tanaz Dhondy speaks at the IACRR Workshop 2018.

Hosted by the Centre for Coastal Reservoir Research (CCRR) at the University of Wollongong, the world’s first international workshop on coastal reservoirs (CR) was held in collaboration with the International Association for Coastal Reservoir Research (IACRR).

“Major cities around the world are actively pursuing coastal reservoirs as a sustainable solution to their water problems. CR is an innovative technology that can recover floodwater entering the sea without desalination,” said the IACRR in promoting the workshop, which invited water resources planners, researchers, engineers, and scientists to review and assess the feasibility of coastal reservoirs in securing universal and equitable access to safe and affordable drinking water.


For civil and structural engineering firm Costin Roe Consulting, winning the 2016 ACSE NSW structural engineering excellence award in the category ‘Unusual Projects’ for work on the Veolia MBT facility at Woodlawn, near Goulburn, brings wider attention to the firm’s role in completing one of the world’s most remarkable eco-projects.

Grant Roe, BE(Hons) MEngSc MBA MIEAust CPEng NER, managing director of Costin Roe Consulting [right], and Mark Wilson, B Eng (Civil) B Surv ME CPEng, director of Costin Roe Consulting [left], with ACSE NSW 2016 award and aerial view of the Veolia Woodlawn MBT facility site near Goulburn, NSW

Grant Roe, BE(Hons) MEngSc MBA MIEAust CPEng NER, managing director of Costin Roe Consulting [right], and Mark Wilson, B Eng (Civil) B Surv ME CPEng, director of Costin Roe Consulting [left], with ACSE NSW 2016 award and aerial view of the Veolia Woodlawn MBT facility site near Goulburn, NSW

A ‘good news’ story for the people of NSW and generations to come, the Veolia MBT facility is transforming much of Sydney’s garbage into the on-site production of green energy, aquaculture, agriculture, and much more as intrinsic value is extracted from the municipal refuse which has caused a mounting problem for the Sydney region.

Few Sydneysiders would realise that each day more than 1,800 tonnes of Sydney’s household and commercial waste is trucked to Banksmeadow where it is compacted and containerised for the 250km rail leg to Tarago – preserving air quality and avoiding the increased costs and risks associated with excessive heavy vehicle transport on our highways. Yet, it was at this point of transition for the waste on its journey to Woodlawn where some of the most significant engineering challenges associated with the project would be encountered by Costin Roe Consulting.

Extreme pavement loads and continuous flow of acids

At the Banksmeadow transfer facility, garbage trucks from participating municipalities arrive fully loaded at 40 tonnes, exposing pavement areas to not just the movement of extreme load weights but also the flow of organic acids produced by putrescible waste. Where conventional concrete pavement and even jointless ‘combi’ flooring would have rapidly deteriorated, structural engineers from Costin Roe Consulting collaborated with concrete technicians to formulate an innovative approach to pavement construction which would maximise its durability in the aggressive Banksmeadow environment.

Innovation using by-product to improve concrete pavement durability

Using a waste by-product of silicon-related manufacturing, silica fume, as an additive to make the concrete more impervious to penetration by liquids and less prone to becoming odiferous, challenges associated with the workability of concrete containing silica fume were overcome to successfully complete construction of the pavement areas required for operational serviceability at Banksmeadow.

Achievement of structural precision despite challenges and constraints

Veolia Woodlawn aerial view 3

Aerial view of reception pit construction, Veolia Woodlawn MBT facility

Other structural engineering challenges associated with construction at the Veolia Banksmeadow site included the presence of a high water-table, the need to preserve an electrical easement which provides one of the main feeds to Sydney’s Eastern Suburbs, and access restrictions imposed by rail sidings on two of the boundaries.

At the Veolia Woodlawn MBT site, structural engineering challenges for Costin Roe Consulting included the design and construction methodology of the reception pit at 13 metres deep, 27 metres long and 12.5 metres wide. Examples of achievement in structural precision included elements such as 24m lengths of pipe installed within a 2mm tolerance, structural beams installed at 25m above ground level within 2mm +- tolerance, and each welded joint being x-rayed and certified.

Leading engineering technology with BIM coordination

Renowned for exceptional capabilities in building information modelling (BIM) technology, Costin Roe Consulting successfully resolved numerous technical challenges inherent to the unique design and construction requirements and constraints at the Veolia sites to coordinate and document all works in BIM.

End result is a win for NSW and all project stakeholders

ACSE NSW award for 'Excellence in Structural Engineering' in the category 'Unusual Projects' 2016 won by Costin Roe Consulting for the Veolia Woodlawn MBT facility, announced in Sydney on Thursday 23 March 2017

ACSE NSW award for ‘Excellence in Structural Engineering’ in the category ‘Unusual Projects’ 2016 won by Costin Roe Consulting for the Veolia Woodlawn MBT facility, announced in Sydney on Thursday 23 March 2017

Today, the Veolia Woodlawn MBT facility produces and exports sufficient electricity to power more than 6,000 homes each year, provides more than 2.5 tonnes of sustainably-grown barramundi to the Canberra market, farms livestock for meat and wool, makes compost, and rehabilitates land which had been contaminated by open-cut mining – all from the mechanical and bio-technical processing of Sydney’s waste.

Costin Roe Consulting completed all civil and structural works for the Veolia Woodlawn and Banksmeadow sites. Civil works included earthwork levels/grading, stormwater drainage, external pavements, car park, modifications to the haulage road, and ponds road. Structural works included all building structures, crane beam, internal pavements, reception pit, push walls, and detailed coordination with services. Over the course of the project, six engineers and two draftsmen designed and documented the works. All structural documentation was completed in Revit.

The 2016 ACSE Award for Excellence in Structural Engineering (Unusual Projects) was presented to Grant Roe, BE(Hons) MEngSc MBA MIEAust CPEng NER, managing director of Costin Roe Consulting, at the ‘Awards for Excellence in Engineering’ event held in Sydney, Australia, on Thursday 23 March 2017.


PROJECT: Veolia Woodlawn MBT facility
CLIENT: Lipman Pty Ltd
SIZE: site 90,000m2 – structures approx. 17,000m2
VALUE: $100M development – $58M construction
COMPLETION: Nov/Dec 2016

2D flood modelling for report by Costin Roe Consulting

Commissioned by Altis Property Partners (developer), via Hansen Yuncken (project manager), Costin Roe Consulting undertook an overland flow (flood) assessment of 193 hectares of land in Orchard Hills, Sydney. The assessment was required to accompany an application for rezoning to facilitate the development of new industrial facilities on a 43.85-hectare subdivision.

2D TUFLOW hydrodynamic modelling by Costin Roe Consulting assisted in gaining the go-ahead for the proposed development – unlocking formerly unusable land to create business and employment opportunities, and improving the management of overland flow for the site and other land in the vicinity.

The assessment prepared by Mark Wilson, B Eng (Civil) B Surv ME CPEng, Associate Director (Civil Engineering) of Costin Roe Consulting, first involved building two-dimensional TUFLOW hydrodynamic modelling for peer review by Worley Parsons, the engineers of a flood study of the area by Penrith City Council. Assisting Mark Wilson with the detailed programming and configuration of the TUFLOW modelling was Mitchell Cross, one of Costin Roe Consulting’s team of flood modelling engineers with TUFLOW modelling engine expertise.

To achieve peer-reviewed validation, Costin Roe Consulting’s TUFLOW modelling was used by Mark Wilson to simulate the occurrence of a range of probable flooding scenarios on the area – in its undeveloped state – to show the accuracy of the firm’s two-dimensional modelling performance against the accepted numerical data.

2D flood modelling for report by Costin Roe Consulting

2D model of the 1% annual exceedance probability (1% AEP) flood levels in the Mamre West Precinct (before construction of the proposed development) as built by Costin Roe Consulting using TUFLOW hydrodynamic modelling technology.

Next, Mark Wilson used the validated TUFLOW modelling-build to calculate and illustrate the differences in flood levels, velocity, and general hydraulics for the same range of probable flooding scenarios following construction of the proposed development, which would happen in two stages.

Finally, the two-part assessment Overland Flow Report Stage 1 and Stage 2 by Costin Roe Consulting successfully informed the NSW Department of Planning & Environment, Penrith City Council, development partners, and various stakeholders on the mitigation and management of land overflow at the site during and after construction of each stage of the project.

As a result of the scenarios produced by the 2D TUFLOW modelling in the Costin Roe Consulting assessment, it was demonstrated that a large percentage of this flood-affected land could be developed, and was suitable for rezoning, which would allow the Altis-proposed industrial development to proceed.

Costin Roe Consulting’s mastery of the TUFLOW modelling engine, and expertise in producing two-dimensional simulations of floodwater behaviour pre/post-development, enabled everyone – including the broader community following exposure of the proposal – to more easily appreciate the benefits offered by the development proposed by Altis, and more favourably consider the statutory changes needed to allow civil works and construction to begin.

Area formerly categorised as ‘high hazard’ due to overland flow

The site proposed by Altis for the development of major new warehousing and logistics facilities was the 43.85 hectare subdivision of a larger parcel of land zoned ‘Rural Residential’. For the proposed development to be given the go-ahead, the State Environmental Planning Policy (Western Sydney Employment Area) 2009 would need to be amended, and the land rezoned ‘General Industrial’.

Located at 585-649 Mamre Road, Orchard Hills, the site lay within what is known as the Mamre West Precinct. The site was identified by Penrith City Council in the report known as the South Creek Flood Study (Worley Parsons) on the Mamre West Precinct as being affected by overland flow associated with adjacent South Creek.

During overland flow events as detailed in the South Creek Flood Study, floodwater on the undeveloped site would be shallow and of low velocity except for the north-west corner, where slow-moving water could potentially reach 1.1m in depth. This area had been categorised by Penrith City Council as a ‘high hazard’ zone.

With a residential area to the north of the proposed development, and Erskine Park Employment Area on the eastern side, Altis and its project partners would be compelled to show conclusively that the civil works planned to make the 43.85-hectare site viable for development would not increase the risk or hazard of inundation for properties neighbouring or upstream/downstream of the development when completed and the overland flow from South Creek re-occurred.

Development would provide new access road and formal drainage system

Mark Wilson, Associate Director (Civil Engineering), Costin Roe Consulting

Mark Wilson, BEng(Civil) BSurv ME CPEng, Associate Director of Costin Roe Consulting, took the lead role in the flood-modelling assessment for the proposed Altis development at Orchard Hills.

Costin Roe Consulting’s easy-to-understand TUFLOW modelling successfully demonstrated how the Altis development would ultimately mitigate and improve the management of overland flow on the site and surrounding area. This would be achieved via engineered land-filling and the building of infrastructure, including a formal drainage system, where none had existed before.

A new access road would be constructed as part of the development project and handed over to the City upon completion. Previously unusable land in a district with prime accessibility to greater Sydney would be made serviceable. More jobs would be located in the far western suburbs of Sydney, handy to residential population centres where the types of land suitable for new industrial developments are in short supply.

Rigorous examinations and consultations involving two levels of government

However, with the Department of Planning & Environment (NSW) the consent authority for zoning amendments under the State Environmental Planning Policy (Western Sydney Employment Area) 2009, and Penrith City Council as a key authority to be consulted due to Section C3.5 of Penrith City Council Development Control Plan 2014 and its guidelines for flood-liable lands, the development proposal had to satisfy rigorous examinations and consultative processes involving these authorities. This is where the external scrutiny of the Costin Roe Consulting 2D TUFLOW modelling-build by Worley Parsons helped meet the high standards of diligence applied by the two levels of government.

Positive feedback throughout the modelling process

“The Mamre Road flood assessment for Altis and Hansen Yuncken involved a high level of consultation with Penrith Council, NSW Department of Planning, and peer review by Worley Parsons. We received positive feedback throughout the modelling process,” said Mark Wilson of the Overland Flow Report Stage 1 and Stage 2 by Costin Roe Consulting. “We will be completing more 2D flood assessments of this nature in future.”



Ask about 2D TUFLOW modelling
Accent Apartments - Structural Analysis

Meeting the demand for expert deployment of BIM technology and more efficient project documentation control throughout the construction industry, Costin Roe Consulting now offers a professional BIM Coordination Service for the documentation of projects from design to completion and beyond.

“Costin Roe Consulting is traditionally at the forefront of engineering technology. We were among the first engineering firms in Australia to make the transition from CAD to the more sophisticated BIM environment. Since then our leadership in BIM has become well-established in the construction industry,” said Grant Roe, managing director of Costin Roe Consulting. “To extend the availability of this expertise more broadly, the establishment of a functional BIM coordination service was a logical step for the firm.”

What does BIM coordination mean?

Accent Apartments - Structural Analysis

Accent Apartments – Structural Analysis (BIM by Costin Roe Consulting)

BIM coordination by Costin Roe Consulting ensures that project documentation will be properly managed from start to finish. The service can be customised to suit individual project requirements. The stages and activities outlined below provide a typical example of BIM coordination workflow:

  • BIM Project Brief: Prior to commencement of the documentation process, a BIM Project Brief meeting will take place between disciplines/consultants and builders/clients. The meeting is to establish the scheduling, naming conventions, model co-ordinates, file transfer methods, BIM version to be used, and to identify which work-sets we can utilise during project documentation. A clear project brief ensures coordination runs smoothly by confirming that each discipline knows what their role and responsibility on the project is, and how best to achieve satisfaction for the client.
  • Client Needs: Client involvement at the BIM Project Brief meeting will allow determination of the level and extent of documentation required for the project to ensure that client needs are satisfied. This can include:
    • Clash Detection: This can be done through Navisworks to check various disciplines to ensure there are no issues once construction on-site begins. It also opens the dialogue between consultants to ensure client gets a fully integrated and co-ordinated model.
    • Scheduling: Creating smart schedules for quantities to help both client and stakeholder requests (eg: steel orders, concrete batch orders).
    • Accent Apartments - Structural Architectural Model

      Accent Apartments – Structural Architectural Model (BIM by Costin Roe Consulting)

      Development: Helping to shape the client’s BIM needs for the future by frequent discussions and ongoing support on any BIM project, so that future projects can run smoothly by utilising the BIM environment.
    • 4D: Moving toward ensuring the progression into the 4D BIM environment which allows us to move into Project Phasing and animation simulations to establish construction sequencing.
    • Milestones: Working closely with the builder’s design management team, the Costin Roe BIM department can ensure that nominated milestones are met, and thereby ensure builder/client requirements are being achieved.

The enduring benefits of BIM coordination

The proper BIM coordination of project documentation enables future use of project documentation data. Clients inherit the asset of the BIM database for their completed building. This database can be used for more efficient client facility management, and as a ‘live’ reference for any future expansion or modification of the facility as clients’ requirements arise.

Carnes Hill development (BIM by Costin Roe Consulting)

Carnes Hill development (BIM by Costin Roe Consulting)

BIM coordination by Costin Roe Consulting ensures harmonisation and proper coordination on the project, helping to grow relationships between all consultants working on the project, and maintaining best practice in the way BIM is being used.

“Members of Costin Roe’s BIM department have been taking part in Consult Australia’s discussions towards implementing a BIM mandate in Australia. We are involved with the Digital Built Environment Task Group to ensure the industry’s BIM needs are identified and met. As a by-product of this worthwhile industry role, we can also be certain that Costin Roe’s future trends are absolutely aligned with the evolving face of BIM,” Grant Roe said.

Costin Roe anticipates a bright future for BIM, both with project documentation excellence and industry growth. As the industry grows, the BIM environment will evolve, reflecting an increased demand for project documentation using BIM software. This anticipated demand from both the public and private sectors will require increased input from all parties. This is where Costin Roe’s expertise in BIM, now available as a functional BIM Coordination service, will strongly contribute.

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Take a virtual reality tour with Costin Roe Consulting BIM – click image to begin

BIM management by Costin Roe, consulting engineers Sydney

Insufficient understanding of the distinction between torque and tension in structural steel bolting can mean the structural reliability of steel buildings is compromised over time by loose bolts. Prominent engineer, Grant Roe, explains why this problem occurs and how it can be prevented or fixed if detected.

The construction of steel buildings in most industrialised nations is regulated by standards. In Australia, AS 4100 sets out minimum requirements for the design, fabrication, erection, and modification of steelwork in structures.  AS 1252 specifies requirements for the high-strength steel bolts and nuts used in steel structures. The bolt tension specifications for certain joints are critical to the performance of the steel structure. However, in the gritty, real-world conditions of a typical construction site, these exacting specifications are not always achieved.

Structural steel bolt tension testing“During inspection of steel buildings we often find structural bolting that is nowhere near the degree of tension required,” said Grant Roe, BE(Hons) MEngSc MBA MIEAust CPEng, NER managing director of Costin Roe Consulting. “Any steel building with critical friction-grip joints that are held together by loose bolting is potentially dangerous. Moreover, in connections with tensile loads, loose bolts can lead to larger than anticipated beam deflections.”

It might be difficult for building owners to imagine how such lapses in precision could occur in construction, given that some steel buildings found with insufficient tension on structural bolts are relatively new warehouses and industrial complexes.

Structural bolts are typically tightened by construction workers using an impact wrench, a power tool driven by electricity or compressed air, to deliver high turning-power with minimal human exertion but imprecise control.

Bolts are specified as either ‘snug-tight’ or ‘fully-tensioned’. Snug-tight is when the bolt is tightened sufficiently to bring the steel plies (or plates) of the connection close together. This type of bolting is used in connections where the load is primarily carried by the bolt working ‘in-shear’.

Tensile strength diagramIn certain situations, where additional capacity or strict movement control is required, bolts are specified to be fully-tensioned. These bolts are tightened further – beyond snug-tight. The process stretches the bolt and creates a tension force in the bolt. The resulting tension force then acts to clamp the plies firmly together, adding greater strength and stiffness to the connection. “It is interesting and important to note that in these types of connections, the applied load is carried by the clamping force, not directly by the bolt,” Grant said.

High strength friction grip bolt

Diagram of high-strength friction grip bolt.

The structural performance of the connection is fully reliant on the clamping force. Thus it is critical that the required tensile force is generated in the bolt. This can be achieved only when the bolt is properly tightened.

AS 4100 specifies minimum bolt tension that must be created in the bolt for the joint to have sufficient strength and stiffness. The required tension is set to be at the bolts “proof” load, or just below the point where the bolt will yield. This is why the term ‘fully-tensioned’ is used. The bolts are tightened until they begin to reach the limit of their tensile strength.

Torque does not mean the same as tension

How does the construction worker know when the bolt has achieved the required tension? This is a very important question. Insufficient tension leads to low clamping force and poor joint performance. Too much tension can break the bolt during installation, wasting time and resources. Careful control is required therefore to achieve the specified result.

“Torque is not the same as tension,” Grant said. “Torque is the effort it takes to turn something, whereas tension is force in the bolt that creates the the clamping force. In structural terms, it is the clamping force which resists the load, not the shank of the bolt. For the most critical joints in a steel structure, fully-tensioned high-strength friction grip joints, the clamping force must be within a precise bandwidth of compliance to deliver the required performance.”

Torque wrench

The pin clutch of an impact wrench in action.

“In controlled environments such as mechanical workshops, where parts are in pristine condition, a torque wrench can be used to tension bolts to the required specification, which is relative to the size of the bolt,” Grant said. “The torque wrench disengages when the degree of torque reaches the point theoretically required to produce the required tension. Torque can translate into tension with sufficient precision in controlled conditions. However, torque wrenches are not suitable for use in structural bolting because workshops and building sites are very different environments. In construction projects, working with dusty, superficially-corroded bolt assemblies is more the norm.”

Bolts are exposed to dirt and moisture when placed around a construction site in open kegs or boxes for access by workers. The ‘white rust’ seen on galvanised steel when exposed to the elements rapidly causes the surface of the bolt to become coarse and irregular. Dust and debris can accumulate around threads on the bolt. The more irregularities on the surfaces of the bolt assembly, the greater friction when the nut is turned into position, and the greater disparity between measurement of torque – the resistance to turning – and the tension produced by turning.

This creates a significant variation in the torque required to achieve the specified tension in the bolt. It is for this reason that AS 4100 specifies minimum tension, not torque.

Bolt tension calibration service

The base unit of a Skidmore-Wilhelm Bolt Tension Calibrator.

“In controlled demonstrations using a torque wrench and bolts that were somewhat dirty and corroded, as found more often than not on construction sites, the tension delivered is only a fraction of the minimum standard required. What we’ve found in the field with our testing of some steel buildings is a great variance in tension between bolts, or series’ of bolt fastenings, with some tension readings so low as to be non-compliant with Australian standards by a wide margin.”

To achieve the minimum tension, AS 4100 specifies two methods: either by a part-turn of the nut, or by measuring tension using a direct tension indicator device (“DTI”) or washer.

“What we have observed in the field is a general assumption that using an impact wrench to torque-up bolts is sufficient. There is a misunderstanding of what is required and as a result, bolts are not properly tightened.”

“To get bolts properly tightened, the only acceptable methods are part turn of the nut, or using a DTI. The additional tightening to achieve fully-tensioned bolts should be completed as a separate and controlled process that can be audited and checked for compliance. This approach will lead to bolted connections that can achieve the required performance.”

Costin Roe offers testing for structural bolting

“Costin Roe Consulting can assist clients by inspecting steel bolting for compliance during construction stages,” said Grant. “We can also assist with testing the structural bolt tensions on completed buildings should the owners have any concerns.”

“In addition, we can assist with establishing procedures on-site that calibrate and control bolt-tightening procedures that are compliant with the Australian Standards.”


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