Ashgrove - Gresham Street Bridge replacement project
Brisbane City Council is replacing the existing bridge crossing at Gresham Street to ensure ongoing safety and local access for all road users.
|Address||Gresham Street, Ashgrove|
|Ward||The Gap Ward|
|Project outcomes||Replace existing bridge crossing to ensure safety and local access.|
Construction – April 2021 to mid-2022
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About the project
Constructed in 1931, the existing Gresham Street bridge is a two-lane timber bridge with narrow pedestrian pathways. Vehicle access is restricted to 22.5 tonne which limits most large vehicles such as semi-trailers and machinery used to maintain Council roads. The bridge is now nearing the end of its serviceable life and requires replacement.
The existing bridge is also subject to flood inundation during low flood events with an immunity of between 50% and 20% Annual Exceedance Probability (AEP), being inundated once every 2 to 5 years.
The project objective is to replace the existing bridge with a new elevated concrete structure with improved 42.5 tonne load limits and flood immunity while minimising hydraulic, environmental, property and construction impacts. The new 3 span structure will be 37m in length, with a cross section total width of 13.7m to accommodate two wide traffic lanes and a 2.5m shared path on each side. The project will also upgrade the traffic lights at the Gresham Street and Waterworks Road intersection to improve the safety for all road users.
The Gresham Street bridge replacement project is jointly funded by Council and the Australian Government as part of the Bridges Renewal Program.
To facilitate the removal and replacement of the bridge in the current location, Council will construct a temporary bridge parallel to the existing structure. The temporary bridge will be a two-lane structure with a shared pedestrian and cycle path to maintain access for residents of St Johns Wood.
The project will involve:
- Construction of a temporary bridge east of the existing bridge, to maintain access during construction of the new bridge at Gresham Street
- removal of the existing timber bridge and construction of a new elevated concrete bridge
- minor relocation of the St Johns Wood Scout’s entrance to improve intersection safety
- Improved drainage infrastructure on Gresham Street and Waterworks Road
- pavement works and line marking
- upgrade to LED street lighting and traffic signals at Waterworks Road
- hard and soft landscaping, including tree planting.
Construction for the new Gresham Street Bridge at Ashgrove started in mid-April 2021 and is expected to be completed by mid-2022, weather and site conditions permitting.
The majority of the construction works will be undertaken during the day and will take place between 7am and 5pm, Monday to Saturday. Certain critical components of the works will need to be undertaken at night and will generally take place between 7pm and 5am, Sunday to Thursday, when traffic volumes are lowest to ensure the safety of motorists and workers and to minimise traffic disruptions. Council will provide advance notice of out-of-hours works.
During the works, residents and businesses near the bridge may at times experience increased noise, truck movements, vibration, dust and light from mobile light towers (during night works). Council will make every effort to minimise impacts to the local community and provide advance notification of particularly noisy works or out-of-hours activities.
Vibration, noise and dust monitoring will be undertaken throughout construction in accordance with the strict environmental controls to ensure the safety of the community.
Temporary lane closures and detours will be required, with traffic control in place to direct road users.
The inbound traffic lanes on Waterworks Road were re-aligned on Sunday 9 May to facilitate the construction of the temporary bridge structure and a number of associated civil works. These traffic arrangement changes also included temporary relocation of the T2 inbound lane, line marking, guard-rail removal, service locating and installation of new safety bollards. Council has undertaken feasibility studies to explore numerous options to minimise the effect of congestion during construction works and unfortunately due to the constrained nature of access into the St John’s Wood area, the current traffic arrangements have been assessed as the optimum solution.
The temporary alignment changes to the intersection of Waterworks Road and Gresham Street provides a work zone for plant, equipment and workers during construction while maintaining two through lanes on Waterworks Road. Due to Workplace Health and Safety requirements, minimum exclusion zones are required to be maintained between traffic and work area at a lower speed environment to ensure the safety of workers.
The temporary road layout will be in place for the duration of works, which are expected to be completed in mid-2022.
Safe pedestrian access around the worksite will be maintained at all times. Access to bus stops on Royal Parade, Gresham Street and Waterworks Road will be maintained during the works. Gresham Street and Waterworks Road will remain open to all traffic during the works however, motorists may experience some delays.
To enable these works, 71 trees within the project site boundary along Enoggera Creek have been identified for removal. Many of these are non-native or identified as weed species. As part of project rehabilitation, 103 native trees of seven different species will be planted at project completion. A further 1200m2 of shrubs will be planted in the creek and 1500m2 of grass turf will be laid near Royal Parade. All tree removal work will be carried out in accordance with the relevant environmental guidelines and Council will make every effort to minimise environmental impacts.
The project will provide:
- a 100-year design life
- improved flood immunity to the bridge deck level 5% annual exceedance probability (AEP) (1 in 20 years)
- upgrade crossing vehicle load limit from 22.5 tonne to 42.5 tonne
- improved drainage
- more reliable access to and egress from local residential area
- improved intersection safety for all road users at Gresham Street and Waterworks Road.
Project timings are subject to change and weather permitting:
- Detailed design – Complete
- Service relocation works – Complete
- Bridge construction works – mid-April 2021 to mid-2022.
If you would like to provide comments, ask questions or find out more about the Gresham Street Bridge Replacement project you can: