ACCIONA and its Suburban Connect partners have completed all diaphragm walls for the Clayton station box on Melbourne’s Suburban Rail Loop East, marking a key milestone that has enabled excavation of the station box to begin.

123 panels, over a year in the making

The works package involved constructing 123 reinforced concrete diaphragm wall panels across the station box and the underground passenger connection to the existing Clayton Station. Installation began in April 2025 and concluded on 21 May, with the final panel poured during an overnight shift.

What is a diaphragm wall?

A diaphragm wall is a deep underground structure built from the surface before excavation, formed by excavating a narrow trench and then filling it with reinforced concrete. These walls provide structural support and groundwater control during deep excavation.

Adrian Donohue, Supervisor ACCIONA, said the milestone marks a significant transition for the project team. “I’m very proud of the Clayton team and the hard work they’ve put in,” Mr Donohue said. “We’ll see the site continue to transform, and it will bring exciting new challenges.”

Next: excavating the station box

With the diaphragm walls complete, crews have shifted focus to excavating the station box, which will form the foundation for the future Suburban Rail Loop station at Clayton. The station is planned to connect passengers to the orbital rail network from 2035.

The completion of this phase represents a critical step in progressing major underground works safely and efficiently, paving the way for the next stage of construction on one of Victoria’s largest transport infrastructure projects.