Allan Block® Retaining Wall System – Drury Quarry
Located at the base of the Hunua foothills in Auckland, the Drury Quarry is one of the largest quarries and biggest producers of aggregate in New Zealand, servicing the Waikato and the Auckland region up to a quarter of its requirements. The main purpose of the project was the future development of its industrial land and improvements of its quarrying and mining operations.
Design
The Bowers Brothers technical team was contacted by ICB Retaining & Piling regarding a possible design and build project for one of their clients, who required a cost-effective solution. After evaluating some options, including big blocks, the client decided that the Allan Block Retaining Wall system was the best option available on the market. The Bowers’ engineering team worked closely with the project structural engineers, providing specific concept designs for each of the three retaining walls. Due to the heavy machinery that operates on-site, special attention was placed on the loadings and the reinforcement required.
Installation
One of the key installation objectives for ICB Retaining & Piling was to be able to construct the retaining walls independently and simultaneously without inhibiting other contractors developing the surrounding site works. ICB’s in-depth knowledge of the Allan Block Retaining Wall system allowed them to accomplish that very efficiently and in less than 3 months.
The Mechanically Stabilized Earth (MSE) walls were built to heights above 5 metres near the quarry pugmill with smaller sections near the old manufacturing masonry plant. The total length of the three walls was over 600 linear metres, with a total face wall area of 2,000+ square metres.
