Southbank Parklands Promenade Remediation Works

About the project

Pensar was engaged by City Parklands Services for the design and construct of the remediation works of Zone C of the Southbank Promenade. Routine maintenance inspections identified concrete decking units which required structural strengthening to ensure the load capacity of the promenade was maintained.

Key Capabilities

Marine construction and refurbishment works; Concrete rehabilitation and refurbishment works

Project Location

Brisbane, Queensland

Client Name

City Parklands Services

Project Duration

January 2021 - August 2021

Project scope

  • Design of a truss system with jacking rods to redistribute mid span loads on deck units directly to existing foundations
  • Utilisation of canoes and float bricks to gain access to the repair space and install a temporary hanging work platform
  • Breakout of over 5600L of delaminated and drummy concrete on eight deck units
  • Welded replacement of over 230m of corroded steel reinforcement to AS1554
  • Installation of 450+ Galvashield embedded anodes to protect residual reinforcement
  • Reinstatement of Guncrete E to repair area by dry spray
  • Blast and paint of structural steel with EVH3 Duremax GFX epoxy system
  • Floating of structural steel in with canoes and float bricks, built piece by piece insitu
  • Implementation of tensile loads to VSL stress bar by hydraulic jacking
  • Continuity bonding and installation of a sacrificial anode cathodic protection system

Challenges

  • Access proved to be the main challenge in the delivery of these works
  • Pensar gained access through a 990mm gap in the promenade piles via canoes, and utilised float bricks to float in individual temporary working platform pieces
  • Access through the gap in the promenade was only achievable at certain lower tides, leaving the crew only four hours per day to enter, proceed with the install, remove all buoyant aides and leave before returning the following day and restarting this process
  • Once the working platform was installed, the crew were able to access the platform from a hole created in the promenade above. This allowed the crew to operate for generally 7-8 hours a day in waders working up to their chests in the Brisbane River. Once the concrete repairs were complete, the structural steel was installed in the same manner. However, instead of lightweight aluminium scaffold, the largest item of steel weighed over 600kg. A series of chain blocks were affixed to engineered anchor points on the underside of the sound spanning slabs in order to manoeuvre them

Achievements

  • Due to a number of identified construction constraints, Pensar applied an alternative remediation approach, offering several opportunities to the project. Pensar worked with SMEC to undertake condition assessment inspections and confirm that the alternative offer was achievable
  • A bespoke temporary working platform was designed and engineered in unison with Pensar, Benchmark and SMEC to anchor into the underside of sound spanning slabs and support remediation works
  • 3D scanners were used to first scan the site to aid in shop detailing. A trial assembly of the structural steel truss system was completed which then was scanned again and checked against the site data
  • Utilisation of pneumatic tools to eliminate risks of electric tools being used whilst working in water
  • Very high quality of finish on repairs achieved