Legacy Way is a motorway link connecting the Western Freeway at Mt Coot-tha in the west with the Inner-City Bypass at Kelvin Grove in the north, constructed mostly in tunnels deep beneath the inner western suburbs of Brisbane.
The project was approximately 6 km in length with approximately 4.3km being constructed by a driven TBM tunnel in hard competent rock below the high-density urban areas of Toowong, Auchenflower, Paddington, Red Hill, and Kelvin Grove.
SYSTRA Bamser provided specialist tunnel constructability services in three specific phases aligned with the chronology of the BCC’s RfP process. These were:
- An initial ‘proactive’ phase aimed at reducing the cost of the project by clarifying or altering specific technical or physical requirements of the project for the information and action of bidders.
- An ‘intermediate’ phase aimed at interpreting, quantifying, and providing advice to BCC regarding alternate and innovative concepts expected to be proposed by the DCMO bidders.
- An ‘evaluation’ phase where the three proposals were reviewed from a tunnel construction and programme perspective, and advice provided.
To ensure a more affordable project for the Brisbane City Council, the services included detailed consideration of the following:
- Tunnel concept designs including innovative solutions based on value engineering and technical assessment (cross section focus);
- Critical underground engineering design review for both tunnels and other underground structures (ventilation /smoke /electrical and sump structures);
- Technical specification development and review (lining and waterproofing focus);
- Identification, assessment, quantification, and mitigation of tunnel project risks;
- Tunnel options review and analysis;
- Tunnel programming;
- Tunnel logistics analysis;
- Construction methods advice and options analysis;
- Constructability analysis and advice including project staging options;
- Construction site setup, layout and resourcing; and
- Tunnel construction plant reviews and recommendations.
SYSTRA Bamser were engaged by the winning consortium the Transcity Joint Venture (Acciona, Ghella & BMD Constructions) to assist with the tunnel fit out design, engineering, procurement, construction management, cost planning, and value engineering tasks as part of the delivery phase of the project.
At the peak of the civil fit-out of the twin tw-lane road tunnels, SYSTRA Bamser provided seven tunnel engineering staff assisting the JV with delivering the scope of work across the following areas:
- Design management and development of solutions for all major tunnel fit out elements post tunnel excavation;
- Procurement of specialist anchoring, form work, and precast installation equipment for the TBM tunnel corbels and smoke duct system;
- Design management and procurement of all architectural finishes in the road tunnels;
- Construction engineering management and supervision of the tunnel backfilling works to final sub grade pavement level;
- Logistics planning and management for all tunnel civil fit-out activities; and
- Planning and interface management between civil fit out activities and Mechanical & Electrical fit out works.