SH3 Awakino Tunnel Bypass

The SH3 Awakino Tunnel Bypass Project is located in the Waitomo District between Te Kuiti and New Plymouth at the eastern end of the Awakino Gorge. The project replaces the 100-year old single lane tunnel. The 2.3km long two-lane road alignment comprises the construction of two bridges over the Awakino River, and three retaining walls (MSE & bored pile walls) up to 10m high with a combined length of approximately 600m long.

Gaia Engineers was the Lead Geotechnical Engineer of the project. The project consists of more than 200,000 m3 earthworks including a 30m deep mudstone rock cut, ground improvement piles, high tensile geotextiles and wick drains to accelerate the consolidation settlement (more than 1.6m) of 8m high embankment fill on soft ground.  Ground improvements also include a rock fall protection fence at the limestone bluff near the historic Awakino Tunnel.

Construction commenced in October 2019 and official opening was in August 2021. Gaia Engineers provided continuous geotechnical services from the tender in 2017, during the detailed design from 2019 to 2020 and during the construction phase from 2019 to 2021.