Thiess PROJECT: The Lane Cove Tunnel is a AU$1.1 billion, 3.6km twin tunnel that is being constructed in Sydney, Australia. PROBLEM: To address the complexity of the project Thiess decided to develop a 4D model of the overground intersection to aid in traffic management planning and stake holder communication. SOLUTION: JetStream was used as a 4D tool that allowed textures and photographic draping, lighting control, and also directly links to the schedule and CAD drawings. RESULTS: The process of developing the 4D model highlighted a number of issues in the traffic management plans, the current schedule, and in access to critical sections of work.

Thiess Proves JetStream's 4D Value Down Under

A Case Study In Virtual Design & Construction

JetStream TimeLiner was used on a major project in Australia and demonstrated its value, delivering effective 4D review and offering all key project stakeholders a clear common understanding of the design intent, construction plan and current project status.

JetStream was adopted by Thiess Pty Ltd., for use on the Lane Cove Tunnel Project, Sydney, New South Wales. Thiess is one of the leading integrated engineering and services providers operating throughout Australia, South East Asia and the near Pacific. At the time of the award the Lane Cove Tunnel Project was the largest design and construction contract in Thiess' history and thus a significant milestone for the company.

The client is the Roads & Traffic Authority, New South Wales [through The Lane Cove Tunnel Company]. The NavisWorks business partner supporting Thiess is AEC Systems Pty Ltd.

To assist in risk management and communication with the client and community during this high profile project Survey Services (a group within the Technical Services department of Thiess), developed a 4D i.e. 3D + time to show the progress of works over the duration of the project. NavisWorks was evaluated and selected as the solution that could deliver the 4D visualization. The model shows a 1KM section of the above-ground works and includes traffic management, upgrade of bridges, viaducts and other structures, the surrounding terrain and surface excavation activities. The model was well received by the client who used it for internal presentations.

The Background

The Lane Cove Tunnel Project involves the construction of twin, 3.6 kilometre, two-lane tunnels. The project also involves the above-ground construction of new transit lanes, viaducts, and ramps, and the upgrade of numerous bridges, cycle ways, and bus stops, etc., mostly under live traffic conditions.

The tunnel is a key link in Sydney's orbital motorway network connecting the Gore Hill Freeway with the M2. It will result in quicker journey times between the city and Sydney's north-west.

The project is a major build, own, operate, and transfer (BOOT) contract, conducted in joint venture between Thiess Pty Limited and John Holland Pty Limited. The value of the construction project is approximately A$1100M (€700M) and the project should be completed in 2007.

Above ground, the section of works from the Pacific Highway intersection to the Reserve Road Bridge overpass (approximately 1km in length) is considered one of the most challenging. This section of works requires the construction of several viaducts, 20+ retaining walls, the rebuild of all transit roads, the construction of new transit lanes, integration of 4 portals for the new tunnel, 4 new bridge ramps and the associated demolition of existing ramps, and the almost complete replacement of a major 4-lane bridge, all under live traffic conditions and highly restrictive work areas.

Because of the complexity of the project it was decided to develop a 4D model for this section of works to aid especially in traffic management planning and stake holder communication.

The Approach

Work on the 4D model began in mid February, 2004. Due to the complexity of the project it was first necessary to build a set of 2D monthly work sequence snapshots of the construction programme. This was sometimes referred to as the "storyboard". The 2D snapshots were used as a basis for assessing construction and traffic plans, standardising modelling naming conventions, and developing staging strategies when none were available.

At such an early stage in the project, data to produce the required 3D models was often unavailable, incomplete, or erroneous. Hence it was necessary to construct some of the 3D structures from 2D paper drawings, interpret and correct design and existing alignment data, clean up surface models, to produce an initial 3D model. The 3D model incorporated the existing structures and surfaces, the final designed roads, structures and features, the surrounding terrain, all traffic 'strings' (lines of cars) and barriers.

At this point JetStream was introduced, evaluated and selected as the 4D solution. JetStream was recognized as very robust tool that allows textures and photographic draping, lighting control, and also directly links to the programme and CAD drawings.

The first version of the 4D model was presented to project personnel on the 8th of April, 2004. the model was very well accepted. The process of developing the 4D model had highlighted a number of issues in the traffic management plans, the current schedule, and in access to critical sections of work. The model was consequently presented to the executive management of the client, the Road Transport Authority of NSW, on the 13th of May and to their CEO of the 26th of May. The model was seen as an excellent tool for presenting a large amount of information.

By April, a number of major design changes had been made since February 2004 and new survey data was available. Thus a new 4D model was required. The next version of the 4D model was completed by June and presented to site on the 7th of July, 2004. Josef Smogurzewski, Design Director for the Lane Cove Tunnel project, said, "We have found true value in 4D modelling especially for traffic sequencing and construction management on the Gore Hill Freeway section of the job."

The Future

It is clear that 4D models are valuable as a communication tool. However, the effort required to produce the 3D CAD models is considerable and modifications to those models can prohibit the use of 4D models in a dynamic construction planning environment.

In the future it may be necessary to develop techniques that move away from developing complex 3D models when concepts and designs are in a state of flux, for the purpose of rapid '4D prototyping'. Once designs and management plans are nearing final approvals then more complete 4D models can be prepared.
It is anticipated that during the construction phase of the LCT project the schedule will be updated with actual dates. The 4D model can then be used to compare 'as planned' with actual progress. An analysis of such rich information in a visual context may help to guide construction managers to better plan their next steps, focussing on the critical path and both short and long term impacts of their decisions.

Key Lessons

• 4D models of road projects can be useful for traffic management planning, assessing constructability and site access issues, and presenting information to project stake holders in an easily understandable form.
• The quality of the data from the project impacts significantly on the effort required to produce the 4D model. For example, development of the 3D CAD models accounted for more than half of the effort to produce the 4D model.
• High-level skills are required to model such projects. Consequently, such models should be developed jointly between site personnel and a dedicated 4D modelling team.

Acknowledgements

• 4D Modelling Team: Del Rains, Erik Isokangas, Khal Hooper, Simone Haubold.
• LCT Personnel: Josef Smogurzewski, David Polkinghorne, Bill Buckland, Bart Pontey, Matt Perkins, Brendan Donohue.