Moggill Constructions - Civil engineering and building since 1973.

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City Reach Boardwalk Brisbane River - Demolition and Repair Works

Project Description

The City Reach Boardwalk Maintenance Project was situated between 145-175 Eagle Street, the City. It  included the demolition and removal of sections of the structure which were in very poor condition, then reconstruction using precast concrete panels.  The boardwalk is a reinforced concrete structure suspended approximately one metre above the high tide level of the Brisbane River in the Brisbane CBD.  Due to the confined nature of the site and limited access, all lifting works took place using a barge mounted crane positioned in the river adjacent to the site, with demolition works on the structure restricted to small equipment due to strict load limits.

The new walkway panels were transported on trucks from Victoria, loaded onto the barge at the Port of Brisbane and floated up the river to the site.  Once lifted into position the pavers, garden boxes and stainless steel balustrading were reinstated and the boardwalk reopened to the public.

 The second part of the project required concrete repairs and cathodic protection to sections of the remaining structure beneath the boardwalk including pile caps, beams and deck panels.  Tidal variations limited access to the underside of the structure, submerging some of the repair areas for much of the day. Small boats and pontoons were used to gain access beneath the structure and maximise working time between tides.  A protective coating was then applied to prevent further corrosion and extend the life span of boardwalk.

Specific Issues and Challenges:

  • Removing and replacing large segments of the raised walkway structure above the river in very close proximity to nearby buildings using a barge and crane;
  • Demolition of structural elements/segments in very poor condition – requiring temporary bracing to support its own weight during lifting;
  • All access for large materials from the river;
  • Coordinating barge works to minimise disruption to City Cat terminals beside the site;
  • Strict load limits on the surrounding structure;
  • Concrete repairs and cathodic protection in confined spaces below the walkway with access restricted to small boats and pontoons at low tide;
  • Repairs and protective coating on concrete that was well below the high tide level;
  • Contamination of the river

Innovations:

  • Specially designed bracing system for each damaged walkway panel which allowed the sections to be lifted out as complete panels without the risk of collapse;
  • Patented lifting mechanisms to meet our safety parameters.

 

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Project Details

Client
Brisbane City Council

Contract value
-

Project Status
Current

Project Category
Marine