3D modelling of headstocks for elevated Flinders Link Project railway

3D modelling of headstocks for elevated Flinders Link Project railway

Key points

  • The $141 million Flinders Link Project in South Australia will extend the existing Tonsley rail line to a hub comprising the Flinders Medical Centre, the Flinders Private Hospital and Flinders University
  • 3D modelling by InfraBuild Construction Solutions meant headstock bar shapes could be redesigned to suit the requirements of the elevated rail line
  • A full-size template of each reinforcing bar was created to ensure each was fit for purpose

A complex headstock design has been brought to life with 3D modelling software. The result is a support structure enabling a sweeping rail extension connecting Adelaide’s Tonsley Precinct with the Flinders Medical Centre.

Flinders Link Project image courtesy of the Department of Planning, Transport and Infrastructure. Artist's impression for illustration purposes only (landscaping shown at maturity).

Project scope: Nine reinforced headstocks create support structure for 650m elevated rail extension

A series of nine headstocks have been built to create the supporting structure for a 650m extension of the rail line, allowing a single track to be elevated over a series of roads and linking the passenger rail network to the new Flinders Station.

The reinforcing steel challenge: Multi-radius headstock required complex reinforcing design

The original design of the headstock included bars that incorporated compound radii and straight ends with hooks all on the same bar. These bars could not be manufactured on machinery that currently exists so each individual bar had to be analysed and amended to suit what was both achievable and still within the design parameters. Furthermore, there was no room for error as the steel fixers had to assemble these headstocks on site and the placement of each bar was dependent on the position of the bar placed before it.

Pile cap column starters.

“We weren’t prefabricating it in a controlled environment – we were supplying the bars directly to site. There was no room for error.” 

 — Matt Bell, InfraBuild Construction Solutions

Pouring the headstock.
The finished headstock.

The InfraBuild solution: 3D modelling allowed detailed analysis of each individual bar shape

InfraBuild Construction Solutions Cavan took the basic headstock model and then recreated it as a detailed 3D model. Re-modelling the headstock allowed for clashes to be identified and all the bar shapes to be redesigned and then manufactured.

The state-of-the-art 3D modelling machine, the only one used in the InfraBuild group, also helped to facilitate complex compound angles. Its value to the project was that it maintained tight tolerances and it maximised efficiencies by eliminating any secondary operation.

“A lot of work was done analysing each individual bar shape as they varied one to the next. We ended up creating a full-size template for each bar. Once they were made, we’d sit the bar in the template and see if it needed tweaking. That way we knew exactly that what we were sending to site was going to work."

— Matt Bell, InfraBuild Construction Solutions

3D modelling of the headstock.

Flinders Link in a nutshell: Improving public transport and pedestrian access to medical hub

  • Flinders Link will improve public transport, cycling and walking connectivity between the Tonsley Precinct and the Flinders medical hub.
  • The completed project will allow connections to the broader Adelaide rail network.
  • An integrated shared pedestrian/cycle path will be added adjacent to the rail line from the new ramp located at the corner of Sturt Road and Birch Crescent to the new Flinders Station.
  • Expected completion date is second half of 2020.

The Project Team

Client: SA Department of Planning, Transport and Infrastructure

Primary contractor: Gateway South (Laing O’Rourke and Fulton Hogan JV)

Steel supplier: InfraBuild Construction Solutions

Steel fixer: Robar Civil

Article published on Thursday, 12 December 2019

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