The demolition and removal of wharf structures including the removal of 15,000m2 of concrete deck and substructure including timber bearers, joist and concrete head stocks, edge beams and the removal of over 1900 piles.
Liberty Industrial were awarded stages 1 and 2 of the project and are carrying out both stages concurrently due to the client’s tight scheduling requirements.
Due to the dilapidated nature of the wharves, we devised an approach utilising large capacity crawler cranes. Detailed lift studies were carried out to accommodate lifts in excess of 30 tonnes.
The works involve extensive wire and concrete saw cutting plus the installation of large capacity chemset lifting bolts.
The 1900 piles had to be cut a metre below the existing seabed depth rather than completely removed to ensure the ongoing stability of the existing seawall and river bed. In order to remove the piles efficiently, Liberty Industrial engaged OPEC Systems who deployed three full time dive crews dedicated to specific techniques to implement a range of innovative underwater cutting tools and techniques.
Techniques included underwater dredging to expose the pile a metre below the sea bed, specialist riggers to safely sling the concrete protective sleeves which exist on the majority of the piles, underwater hydraulic chain saw to cut the 1700 timber piles and underwater diamond wire cutting equipment to cut the steel and concrete piles.
Stringent procedures and controls are in place including dedicated booms and silt curtains to ensure no discharges into the river.
All suitable timber will be recovered and recycled, with select pieces being used in future landscaping and structural architectural features across the Northshore Hamilton development site.