Bridges

The $1.28 billion CityLink Tulla Widening project involves the widening of a 24km section of three major Melbourne freeways from Melbourne Airport to Power Street including the western section of the CityLink tollway, Tullamarine and Westgate Freeways. The project aims to increase capacity by up to 30 per cent and improve safety.

As part of the Bulla Road to Power Street Design and Construct section of the project, a new interchange bridge at Bell Street near Pascoe Vale Road was required to increase capacity on the existing Bell Street Bridge by shifting Bell Street to Pascoe Vale Road through traffic onto a new bridge, thereby separating them from traffic entering CityLink. The new bridge provides support for single lane of traffic and a shared user path to improve walking and cycling access to the Moonee Ponds Creek Trail.

The 269m long structure is built on a complex brownfields site and spans over the entire CityLink carriageway and exit ramp, Moonee Ponds Creek, Craigieburn railway line and was in close proximity to Strathmore Secondary College. To minimise the impact on the community, the bridge needed to be erected under limited road and rail closures and the lack of space for piers along the alignment resulted in large spans of up to 62m using four span continuous steel box girders on a tight curved radius with skewed supports. A segmental construction methodology was adopted with extensive temporary works. In addition to the main bridge, significant reinforced soil retaining structures were required to widen the existing road embankment approaches.

This paper presents the design and construction challenges encountered by the project team including the development of the segmental erection methodology, 3D BrIM modelling and sophisticated construction staging analysis. Major bridgeworks have been successfully completed, with construction expected to be completed by mid-2017.