10 m High Mechanically Stabilised Earth (MSE) walls were required to retain the fill on either side of the primary crusher at the Hall Quarry in The Australian Capital Territory. A wall system that was quick to install, made use of materials readily available in the quarry and was able to conform to an extremely irregular foundation condition was required.
The wall would also need to withstand the heavy loads imposed by the dump trucks and the vibrations induced by the crusher and blasting within the open pit. It was the opinion of the client that the only wall system that would comply with this strict mandate was the Maccaferri Terramesh® system.
The Maccaferri Terramesh system consists of a Gabion type facing with integral woven mesh reinforcement that extends back into the fill material thereby increasing the shear properties of the backfill to create a “reinforced block”. The woven mesh is Galmac coated (95% Zinc 5% Aluminium Alloy) with an additional 0.5 mm radial thickness polymer coating to address any long term durability concerns.
A site inspection was conducted at the quarry in May 2005 (10 years after completion), to carefully scrutinize the long term performance of the structure. There was no visible damage to the polymer coating, the mesh was in excellent condition and the Gabion facing showed no signs of fatigue or overstress. A spokesman for the quarry indicated that they were extremely happy with the overall performance of the structure.
Another site visit was conducted in March 2019 and once again, the client reitterated how happy they were with the performance of the Terramesh walls.
Hundreds of Terramesh® walls have been constructed to date in Australia up to 22 m in height with vertical walls in excess of 32m high constructed overseas using this innovative solution.