Rozelle Interchange Project – Platipus® B6 Anchors

As part of Sydney’s WestConnex road project, the mostly underground Rozelle Interchange provides connectivity to the M4M5 Link Tunnels and the City West Link, as well as an underground bypass of Victoria Road between Iron Cove Bridge and Anzac Bridge. The Rozelle Interchange will also provide connection to the future Western Harbour Tunnel.

On the approaches to one of the bridge structures, temporary sheet piling was needed to allow the new bridge to be constructed beside the existing one. As propping wasn’t an option, the sheet piles need to be anchored to minimize the depth and strength of the sheet piles. With tight timeframes, minimal geotechnical information and restricted access, the contractor contacted Cirtex for a solution using the Platipus Anchor system.

DESIGN

With ground conditions consisting of crushed sandstone with large cobbles of up to 300mm, the sheet piles were anchored using Platipus B6 Anchors, installed to 6m with a required loading of 100kN per anchor. The Platipus Anchors were installed through the sheet piling after the top half of the sheet pile was exposed. Each anchor was load locked and tested to the required proof load allowing the remainder of the excavation to take place.

INSTALLATION

Cirtex was present at the commencement of the installation on site to provide support and training. The Platipus B6 anchors were installed through the compacted sandstone and back filled to the required 6m depth using a 6-ton excavator with a breaker. The anchors were installed quickly and easily with approximately one anchor installed and tested per hour.

The Platipus® B6 Anchors provided the following benefits to the project:

• Quick and easy to install.
• Support is achieved instantaneously once loaded and locked.
• Achieves excellent anchor loads.
• Was simple and easy to install into the compacted sandstone even with the larger cobbles present.