Old Jugiong Water Treatment Plant – Platipus Anchors

The Old Jugiong Water Treatment plant in NSW was originally constructed in the 1930s and upgraded in 1991. Further expansion works and an overall upgrade in 2021 identified that two existing retaining walls required strengthening. The client preferred to enhance the existing structures, as opposed to deconstructing and rebuilding, to get each wall through to the end of their required service life.

Cirtex worked with the engineers on the project in the initial stages, using our knowledge of retaining and earth anchoring to assist with determining the best and most cost-effective way to further extend the retaining wall’s design life.

DESIGN

There were a number of separate design issues to be overcome on the site. A section of the cast-in-place concrete retaining structure required additional support to reinforce the existing wall, and in one part of the wall contractors had to remove existing, failed support from in front of the wall in order to install new reinforcement. Another section needed additional anchors inserted into the wall and then overlaid with shotcrete to protect and stabilise the face.

Cirtex supplied and assisted with the install of a mix of B6 and B8 anchors, driven to approximately 6m in depth. The loads ranged from 70kn to 150kn ultimate loads, with some areas requiring a single row of anchors, while others required a second row.

A total of 45 Platipus B6 and B8 anchors were used in the different areas depending on the soil conditions that were found along the alignment of the wall.

INSTALLATION

The major benefit of the Platipus Anchors in this case was that the contractors could retrofit the old wall and effectively stabilise it. As it was deemed too expensive to remove all retaining walls and build new ones, especially in an already aging facility, the Platipus Anchor solution allowed contractors Ormond Civil to relatively simply, quickly and cost effectively anchor the wall and give the wall the additional support to get the entire plant through to the end of its design life.

Cirtex provided training specific to the Platipus solution to the Ormond Civil team, as well as ongoing support. The project began at the height of the unprecedented covid restrictions. Unable to go on site, Cirtex continued to provided support via video calls and phone calls while Ormond Civil were doing the installation.

The Platipus Anchoring system provided the following benefits to the project:

• The ability to retrofit anchors into the existing structure
• Installation with portable lightweight equipment
• Installation without using grout or drilling fluids which is kinder to the environment