Stonehill Business Park – MagnumStone™ MSE Wall

Located in Wiri, Auckland, Stonehill Business Park has transformed a former quarry site into one of the region’s leading industrial and logistics hubs. Development of Stage 5 expands the park further, providing new warehouse platforms and access for heavy vehicles.

To maximise usable land along the southern and western boundaries bordering Puhinui Creek, the project required a large retaining wall system that could deliver stability, durability, and efficient construction within the site’s tight environmental constraints.

DESIGN

With Puhinui Stream and wetlands at the toe of the slope, overall site stability was a key design consideration. Cirtex was engaged to deliver a full MagnumStone retaining wall solution, including detailed design.

The resulting wall spans 320 metres in length and reaches a maximum height of 9.14 metres, following the natural curves of the creek. To address bearing and global stability challenges, a Mechanically Stabilised Earth (MSE) design was used with StrataGrid geogrid. A hybrid MSE and Gravity retaining wall design was utilised in areas where warehouses sit close to the wall crest.

The gravity portions of the MagnumStone wall are supported by extenders and do not require geogrid. This creates a clear zone at the top of the wall for services and future building foundations. This hybrid design provided both geotechnical performance and layout flexibility while maintaining a consistent wall face.

INSTALLATION

Construction began at the lowest point near the stream before progressing westward in stages. StrataGrid reinforcement was installed in varying lengths to meet stability requirements, with engineered fill compacted in layers.

Euroclass selected MagnumStone for its near-vertical face angle and modular system, enabling them to maximise developable land and self-perform construction without specialist contractors. The lightweight blocks and fast installation process condensed the construction programme while minimising disturbance to the stream and wetlands.

With the retaining wall now complete, new warehousing and pavement construction are underway – trransforming previously unusable land into valuable industrial space and extending the growth potential of Stonehill Business Park.

The MagnumStone system provided the following benefits to the project:

• Versatile design combining MSE and gravity wall sections
• StrataGrid reinforcement mitigates global stability risks
• Near-vertical face maximises usable land area
• Fast, efficient installation with standard equipment
• Durable 100-year design life for long-term performance