The Bridge Mall redevelopment is revitalising the historic retail precinct in the centre of Ballarat.
The significant project has already led to new investment in the Bridge Mall, with the redevelopment of Norwich Plaza underway and businesses planning to open in the mall.
Once completed, the redevelopment will showcase a range of design features including an illuminated portal to the Yarrowee River.
The Yarrowee River flows underneath the mall, stretching from the Big W car park to Alfred Walk at Norwich Plaza, across the centre of the mall and under Coliseum Walk.
The 1871-built brick and steel Yarrowee River bridge that has been enclosed underground as part of the mall and uncovered as part of the works, is heavily corroded – significantly more than anticipated.
To ensure pedestrian and motorists’ safety, as well as a certified load rating for the bridge to meet modern standards, the structure is expected to be replaced. A new bridge design is being explored, with the project team seeking to achieve a timely and cost-effective outcome.
Given the historic nature of the area, the 153-year-old bridge is one of a number of latent conditions (existing structural issues) that the construction team has encountered that require rectification.
While many of the issues were anticipated, the extent of rectification works required has been more significant than expected and could not have been reasonably anticipated during the design phase.
The Bridge Mall sits above a surrounding floodplain on top of a highly contaminated alluvial mining landscape. This area has been subject to significant change over the years, resulting in challenging ground conditions.
The swampy sub-grade has proven particularly challenging from a construction perspective, resulting in the need to remove more contaminated soil from the sub-grade than expected. Additional reinforcement has been required to provide a solid foundation for the construction of the new space and carriageway.
The excavated material removed was also more contaminated than expected, with a higher proportion of Category B soil, resulting in a higher cost of disposal.
A quarterly financial report to be considered at the February Council meeting on Wednesday night will outline a request for an additional $4.7 million that needs to be allocated to complete the project.
If approved, the additional $4.7 million would:
- Cover current variations that have been identified to date, including bridge replacement, subgrade rectification, asbestos telecommunication pit replacements, other latent conditions and non-discretionary costs
- Technical consultant fees to address the poor subgrade, contaminated soil, archaeology, bridge investigation and redundant services, pits and structures, and
- Include a 10 per cent contingency to cover any further latent conditions.
The revised project budget would total $23.3 million if approved.
Works undertaken since the project began in July include:
- Demolition of the centre of the mall, including removal of three fixed canopies, street furniture and pavers, and removal of remnant sections of tram track dating back to 1905 in accordance with heritage approvals
- Named pavers removed, stored safely and ready to be laid in the new streetscape
- Bulk excavation from the Peel Street end of the mall right through to Grenville Street, including removal of a significant amount of contaminated soil
- North and south stormwater pipe installation
- Coordination with Central Highlands Water as they replace water mains through parts of the construction zone
- Night works to remove and dispose of asbestos-containing telecommunication pits, and installation of new communications pits
- Installation of services, traffic signal pits and electrical conduits for smart street lighting
- Installation of smart poles, which will light the space and highlight historic facades. These will also be equipped with power supplies and CCTV
- Installation of tree pits to support the growth of the new landscaped gardens
- Reinforcement and stabilisation of the material beneath the carriageway (known as the sub-grade)
- Concreting to forge the base of the road alignment and planned central event space
- Concreting of footpaths in preparation for paving works
- Removal and cutting of bluestone salvaged from the former La Trobe Street saleyards
- Opening up the portal to the Yarrowee River
- Demolition and excavation of Time Lane
- Commencement of kerbing works.
