A complex and challenging project, The Carlin Hotel in Queenstown consisted of 84 bored piles to form the retaining structure for a new luxury hotel. Piles were 900mm, 800mm and 750mm DIA with depths ranging from 14m to 24m. Given the geometry of the site piling equipment was craned in from Kent Street, sheet pile staging was established to form working platforms for each of the tranches. Due to the perched water, low strength lake sediment silts and loose granular layers a combination of segmental casing and drilling polymer was used to allow successful construction of the piles. All piles were tremie poured. The proposed methodology for the retaining wall included the phased excavation and installation of shotcrete to the upper portions of the retaining wall. Following the second risk workshop with the consultant team and Moore Construction, it was identified that reverting to the original proposal for infill piles would be more cost effective and assist in reducing the overall programme.
Concrete capping beams, buttress slabs and floor slabs, this was the second stage of the retaining/foundation works. This consisted of a 1.2m x 1.1m concrete beam around the top of piles. Each of the caping beams had to be 30mpa at 7 days to allow excavation stage by stage. Excavation was done in 1.5m drops and halted to measure deflection in the wall, after this time had passed and deflection was within the allowable limit’s excavation progressed.
All works where completed utilising Moore Constructions plant & labour resources. Hallenstein Street illustrates Moore Constructions ability to perform on large scale contracts, meet tight contractual programmes, produce quality work and familiarity with technically challenging geological formations and soil conditions.
