Riley was engaged to provide geotechnical input for the 210-lot Kauri Landing residential development in Takanini, Auckland, within tight timing.
The delivery timeframe did not allow for the difficulties in carrying out site development works in the soft and compressible peaty soils underlying the site. It also did not account for normal attenuation of fill-induced settlement.
In collaboration with the overall project team, we identified and completed surcharging as a suitable solution to reduce the fill-induced settlement timeframes.
For the surcharging, 38,000m3 of peaty soils were imported to the site from a nearby project. This material would otherwise have been cut-to-waste.
Completing 210 affordable homes within the compressed timeframe will significantly benefit the local community. All lots were handed over on the target dates and construction of the homes is almost finished.
The Riley technical solution reduced the settlement attenuation timeframe from 180 days to 40 – directly shaving 140 days off the construction programme. The lot delivery dates couldn’t have been achieved without the surcharging.
Once surcharging was finished, the 38,000m3 of imported material was used for bulk fill across the rest of the site. This saved about 6,000 truckloads being cut-to-waste. It also saved about 2,200 truck movements on local roads, together with associated emissions.
Other successes from surcharging:
compliance with resource consent conditions was demonstrated to Auckland Council
sustainability benefits included reductions in wasted material, truck movements, carbon footprint and exhaust pollution.