Dormer Construction

HSBC BUILDING DEMOLITION

LOCATION Cambridge Terrace, Christchurch
CLIENT Farry Clear Limited
VALUE $925,000
PROJECT START March 2012
COMPLETION June 2012

SCOPE

Complex demolition of ‘eccentric’ main structure requiring critical sequencing. The building comprised a perimeter moment-resisting seismic frame with gravity beams and columns internally. The perimeter seismic frames step in sequentially as the building rise and seismic demands reduce. As the rectangular seismic frame columns reduce they are replaced with purely gravity load resisting circular columns. The flooring comprised of a hi-bond steel tray reinforced concrete floor system spanning some 5.2 metres between the perimeter frames and internal gravity beams. The roof (26 metres above outside ground level) was lightweight steel cladding upon a structural steel frame. The south wall was constructed on the boundary and the majority of the frame in-filled with pre-cast concrete wall panels. The lift core structure was some 33 meters high.  DCL produced 3-D modelling to assist the client and staff in understanding the demolition sequence. This modelling provided a basis for analysing stability of the building at each stage and ensuring sight lines for the high excavator operator were maintained.

PERFORMANCE

Programme

Applied logical sequence to achieve completion of works in 3 months. Asbestos removal, retrieval of tenant items, soft strip out, protection to adjacent buildings, roof removal, pre-cast concrete removal, main building de-construction.

Environment

DCL carried out dilapidation survey (supplied to CERA), asset protection, service disconnection and building monitoring.

The project involved the protection of adjacent buildings including the Harley Chambers, a listed historic building, sited approximately 1 meter from HSBC work boundary.

Health and Safety

Nil incidents. DCL carried out building stability monitoring using vertical surveys and crack monitoring during demolition and after significant earthquake after shocks.