Project Overview
Moore Construction delivered the construction of three secant pile retaining walls along the Mangaone Stream, both upstream and downstream of the Tremaine Avenue Bridge in Palmerston North.
The project formed part of critical infrastructure works to stabilise the stream corridor, protect surrounding assets, and improve long-term resilience of the waterway.
Award Recognition
Moore Construction was recognised with a Civil Contractors New Zealand (CCNZ) Award for outstanding delivery of the Mangaone Stream Retaining Wall project.
The award highlighted the team’s ability to overcome significant logistical challenges, material constraints, and complex piling conditions while delivering a high-quality outcome.
Engineering Solution
The primary structural system consisted of CFA secant pile retaining walls, formed using 340 piles at 750mm diameter to create a continuous in-ground wall system.
A 173-metre reinforced concrete capping beam was constructed to tie the pile system together, ensuring structural continuity and performance.
Construction Delivery
- Temporary access platforms for piling operations
- Sheet piling for stream diversion
- Erosion and sediment control systems
Overcoming Complexity
The project presented significant challenges including constrained site access, regional resourcing limitations, and demanding ground conditions.
Moore Construction worked closely with suppliers — particularly in developing the appropriate concrete mix design — ensuring performance requirements were met under site-specific conditions.
Mobilisation to the North Island and execution in a remote environment further demonstrated the team’s adaptability and delivery capability.
Additional Works
The project also included stream channel improvements and long-term erosion protection:
- Removal of existing gabion structures
- Bulk excavation of streambed
- Placement of engineered rock riprap
