Earthworks are currently being undertaken to lower the freeway so that future traffic noise is minimized. This was a specific requirement negotiated by the Mitchell Freeway Extension Project Community Reference Group during the early design stages of the project.
“In order to lower overall height of the new freeway extension, tonnes of earth had to be removed from the existing ground level. However, there is lots of naturally occurring limestone at this depth which has to be ripped and broken down so the material can be cleared away,” said Project Engineer for Earthworks Leon Fogliani.
“Just like when you compact sand to lay new backyard paving, the soil needs to be watered and tightly compacted. This helps the material achieve its highest density and removes any voids. Road pavement needs to be laid on a strong, dense base to ensure sufficient pavement strength,” he said.
The construction method has been chosen as it is safer and less noisy than drilling and blasting but noise and vibration still occurs when making the embankments and cutting the limestone.
An 80 tonne bulldozer and various compacting rollers have to be used to move and compact the sand enough to achieve maximum density. This will ensure that the freeway design life can be achieved to high standards of quality that the Mitchell Freeway project team is strongly committed to.
If you have any questions or concerns, please contact the project Community Relations Advisor on 1800 231 612.