Bypass bridges and tunnels underway

Bored piling has started on the new twin bridges at Pine Brush Creek, part of the Coffs Harbour Bypass project.

Work commenced on the western side of the Pacific Highway recently and each two-lane bridge (north- and southbound) will take about three weeks to complete. Each bridge requires seven bored piles with two abutments.

The work involves building pads to create stable footings for piling rigs, transporting the rigs to the site, drilling through soil and rock to form pile holes, installing steel reinforcement, and stockpiling soil and rock for use in other areas of the bypass.

According to Transport for NSW, it also involves delivering concrete from the site’s batch plant on Englands Road, North Boambee, pouring the concrete into the pile holes and using pneumatic drills to remove concrete overpour. Once the piling for the northbound bridge is complete, the abutments and substructure will be built.

The Coffs Harbour Bypass project team has also started tunnel portal preparation at the Gatelys Road tunnel, one of three tunnels on the bypass. The work includes installing horizontal piles and steel arch frames to support the tube canopy, stabilising the exterior of the tunnel portals with large bolts and reinforced sprayed shotcrete, and excavating the entrance to the tunnel portals.

Other work will include the installation of noise barriers, establishing a temporary work site, building a temporary water treatment plant, installing a ventilation system and air quality monitoring, environmental controls, and building site access and internal roads.

Image: NSW Government.

About the author

Desi Corbett

Desi is our weekly news journalist and the editor of Concrete in Australia magazine for 10 years. She has been heavily involved in all forms of engineering since 2013; part of a 30-year writing career across a range of subjects and media.