North Island Main Trunk (NIMT) Bridge Construction

NIMT Bridge Construction was a significant project undertaken by Spiral Drillers, involving the foundation work for three new bridges spanning the rail lines. The scope of work included the installation of 48 Bored Piles, ranging from 900mm to 1200mm in diameter and reaching depths of up to 29.5 metres. Piles were founding in dense sands and required full length permanent casings to be installed to the pile toe.

To provide ground improvement under the bridge abutment locations, 18 metre UC beams were driven into the ground.

The project demanded a diverse range of piling techniques to construct the permanent works. Spiral Drillers collaborated closely with Fulton Hogan to develop a tailored methodology that would suit the existing platforms. Leveraging our extensive expertise, we mobilised additional equipment to complete temporary works, facilitating the smooth progression of pile and follow on construction.

NIMT Bridge construction saw Spiral Drillers actively piling on three separate work fronts for an extended period of time, operating during both day and night shifts. Our operations involved the utilisation of five Crawler Cranes, three Drill Rigs, and various other ancillary equipment.

We played a vital role in the development of the construction methodology, ensuring a high level of design satisfaction and constructability from an implementation perspective.