The microtunnelling project in Victoria’s southeast involved burrowing more than 100 m beneath the major rural highway Princes Way and the VLine railway to make way for a new pipeline.
Edge Underground carried out the microtunelling project using Vermeer’s Axis vacuum microtunnelling method and HOBAS-supplied pipelines, with Fulton Hogan as the principal contractor.
Edge Underground Managing Director Stuart Harrison said the ground conditions and a risk of failure were the key reasons for Gippsland Water and project consultant GHD to opt for slurry and displacement microtunnelling.
“Many challenges had to be overcome in order to deliver a tight tolerance in vastly changing ground conditions,” said Mr Harrison.
“The use of a 350 mm pilot shot as a form of geotechnical sample proved to be a significant factor in delivering a successful project without requiring any additional shafts.”
The works, which follow more than two years of planning and design in consultation with VLine and VicTrack, were completed over two nights without any impact to train services.
Gippsland Water General Manager of Customer Service and Communications Paul Clark said the operation was the second of three critical sections of the final phase of the Warragul Central Trunk Sewer Replacement project.
“This investment allows for future development of the Warragul township along with fast-growing areas to the west and south of Warragul,” said Mr Clark.
“Previously un-sewered properties close to the Warragul CBD will also be serviced.”
Once operational, the new sewer main will have emergency storage capacity within the pipeline system, allowing Gippsland Water to decommission two existing pump stations currently located on the western edge of Warragul.