Etham Avenue, Darling Point, Sydney

An existing masonry retaining wall, up to 2.5m in height and built in the 1970’s, was showing signs of instability. Cirtex Australia with the Engineer, MYD Consulting, developed a remedial stability solution using Platipus anchoring systems. The system would minimise disturbance to the existing wall and eliminate the total dismantling, design, and construction of a new retaining structure.

Design

Platipus B4 anchor systems were used to stabilise the existing retaining wall and driven up to 5.4m from the wall face into an unknown sandy backfill. No geotechnical or soil information was available at the time of the installation, but once installed to the required depths, they could be immediately tensioned, load locked and the ‘Design’ or ‘Working’ load verified and confirmed. Design life requirement for the remedial works was 25+ years.

Installation

Coring through the 1m existing retaining wall took a total of 3 days to complete the Platipus anchor installation and load testing taking a single day. The anchors were tensioned and extended up to 300mm and ‘Proof’ loaded to 28kN (2.8 tons). All Platipus anchor systems were load locked against galvanised load plates with a small active load of 0.5kN.

Benefits of Platipus B4 Anchor System:

• No expensive demolition and the additional costs of design and construction of a new retaining structure.
• No messy grouting, load uncertainty or delay in testing with immediate load verification.
• Original retaining structure stabilised effectively and efficiently with minimal environmental impact.
• With no, or minimal geotechnical or soil information available, Platipus anchor systems provide immediate load verification and thus design flexibility for anchor sizing and spacing.