Building an empire in New Zealand

The Empire GRP jacking pipe is a game changer, and it didn’t take long for construction company Parkinson and Holland to make the infrastructure solution supplier its sine-qua-non partner in crime for sewer upgrade projects.

The first project was the replacement of a 113-year-old wastewater system on Nixon Street in Whanganui East. Empire Infrastructure director of sales and operations Aaron Mackley said the scale of this project was “quite significant” as it involved 540m of pipe. “It was between 3-7m deep, a pretty challenging project for Parkinson and Holland, because the ground was soft and and sandy clay was present,” he said.

The soft and sandy conditions were identified as an issue prior to commencing work by the contractor. Using a ground improving specialist, Parkinson and Holland constructed vertical jet grouted columns every 2m along the bore path.

As construction got under way, the contractor was also met with archaeological finds. These included middens, which are Māori sites where food remains, bones, and charcoal is buried, and logs from totara trees carbon dated at 4575 years old. These logs proved to be challenging because they would block up the cutting teeth of the machine, so Parkinson and Holland would have to dig down and remove the obstruction, then fill the hole with grout and wait for it to dry before continuing the boring process.

Mackley said that these soft ground conditions were certainly a challenge on this project, as they could have had dramatic consequences on this sewer system upgrade. “Soft ground conditions are always a risk when it comes to these types of installation,” he said. “Contractors are always very wary of these conditions, because it can lead to a project being delayed or possibly having to be completely stopped.”

This was this reason why Parkinson and Holland chose Empire Infrastructure for its Centrifugally Cast Jacking pipe offering, and opted for the installation of 542m of 427OD GRP pipe between 2.8m-7.4m deep through sand, alluvium and clay.

“Parkinson and Holland opted to go with the Empire pipe because of its distinctive features,” Mackley said. “It is a centrifugally cast pipe which has the added value of a smooth outside wall with a low co-efficient of friction, this enables contractors to get through those sticky sandy conditions with ease.”

A similar scenario was replicated on a second and smaller scaled sewer upgrade project in Dunkirk, a coastal city in northern France. Mackley said that even if the project wasn’t as big as the previous one, Parkinson and Holland chose to use Empire Infrastructure’s glass reinforced plastic (GRP) pipes due to the soft and sandy ground conditions.

According to Mackley, the advantages of using a centrifugally cast pipe such as the Empire Infrastructure’s pipe are numerous. “The Empire Infrastructure GRP pipe provides or creates less friction when installing the pipe in those sticky sandy type of ground conditions, and that is a huge advantage,” he said. “Also, our product offering is very cost-effective, and our short delivery times are an advantage to our clients anywhere in the world.” The relationship between Empire Infrastructure and Parkinson and Holland bloomed about three years ago.

“This collaboration has been very beneficial, we have been awarded a number of projects by Parkinson and Holland, and we always look forward to working with them,” Mackley said. “This is because, at Empire Infrastructure, we pride ourselves on the premium services we give our clients and value the relationships we create.”

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