PROJECTS

SH 20 Puhinui Interchange

Owner: Transit New Zealand
Contractor: HEB Smithbridge
Consultant: Connell Wagner

Puhinui Interchange is a diamond interchange carrying the dual carriageway SH20 over the eastern access road to Auckland International Airport. The 8m high highway embankments are reinforced with geogrid. Wick drains were installed in the organic sediments beneath the embankments to accelerate the dissipation of pore water pressure. The pair of 75m long, 3 span bridges have prestressed T-Roff (Super-T) beam decks and are founded on bottom driven steel tube piles.

Duncan Peters was responsible for the overall management of the design of the interchange and the design of the bridges. Ka-Ching Cheung was responsible for the overall geotechnical design of the interchange and the design of the pavements and bridge foundations.