Sync Lift Systems Ltd deployed an Enerpac EVO synchronous lifting system to safely raise, re-level and restore an entire 2,800 ton three-storey building that sank up to 300mm during the devastating 2011 Christchurch earthquake.
The shallow 6.3 (ML) magnitude quake in New Zealand killed 185 people and caused extensive damage to buildings and infrastructure already weakened by the September 2010 7.1 (ML) earthquake and its aftershocks.
The cost of damage has since ballooned to more than $NZ40 billion ($A35 billion) with Prime Minister John Key describing the reconstruction project as the largest and most complex in New Zealand history.
One of the most heavily damaged areas was the city’s Central Business District (CBD) where the new generation Enerpac 12-point synchronous technology was deployed by Sync Lift Systems to level a 70-metre long concrete building in Fitzgerald Avenue.
The building was dislodged from its foundations by the earthquake and needed to be raised and levelled in a precision operation designed to optimise safety during the lift and to ensure maximum stability in preparation for reoccupation.
The Enerpac EVO synchronous lifting system employs PLC control of multiple cylinder lifts, a technology that offers accuracy, safety and productivity benefits for precision lifting of heavy machinery, plant and structures.
The EVO system enables one operator to control the entire precision lifting process, during which the status of every lifting point is constantly monitored and displayed. Instead of whole teams of lifting personnel trying to manually co-ordinate the lifts by hydraulic cylinders dispersed around a job, the EVO-Series synchronous lifting system integrates the high-pressure hydraulic cylinders involved with the PLC system to monitor and control precise movement and positioning of heavy loads.
All movements are managed through an integrated HMI from a central control position that displays live operation with real-time status updates for each lifting position.
Sync Lift Systems New Zealand Director Mr Garry Millar explained that the synchronous lift system was chosen to meet the very strict safety and building deflection stipulations; they had to restrict flexing of the building to a range within 4mm a metre, or a total of 24mm over jacking points spread 6m apart.
The lift was staged progressively from one end of the building to the other, with each section lifted incrementally to optimise accuracy and minimise deflection. The process was repeated to raise the building to the required position.
Twenty-two 100 ton and 150 ton Enerpac 700 bar (10,000psi) cylinders were installed on steel stools and connected to the building’s foundation. Some cylinders were connected together and operated as one from one outlet of the system. All hydraulic lift cylinders were connected to the EVO’s pump unit via hydraulic hoses connected.
The synchronous lifting system controlled the extension of the cylinders to safely and accurately lift the foundation and the building to the required position. Once the foundation was lifted to the correct position, the lock nuts were fastened and the foundation and building were fixed in the required position.
The entire project was completed within 21 days and reoccupation commenced shortly afterwards.
Enerpac Integrated Solutions’ Manager Mr Richard Verhoeff said the operation was completed on time with a high degree of safety. He adds that the technology can also be readily applied to infrastructure such as bridges and tunnels and for monitoring, foundation support and structural testing.