By rosebell
While the Roberts Hill Tunnel on New South Wales’s Coffs Harbour Bypass is going under excavation,Transport for NSW says preparatory work at the northern and southern portals is due to be completed before controlled blasting and 24-hour construction operations begin.
With the aim of supporting the tube canopy; stabilising the top exterior of the tunnel portals with bolts and reinforced shotcrete; excavating the entrance to the tunnel portals; installing noise barriers; establishing a temporary work site; building a temporary water treatment plant; installing a ventilation system and air quality monitoring; and building site access and internal roads, the work includes installing horizontal piles and steel arch frames.
The determined time duration for portal preparation work will be from mid-December to late February and following that the team are slated to start controlled blasting and 24-hour working.
As the shortest of the three tunnels on the bypass, Roberts Hill is 160m long.
While the heading digging has been completed on the 410m-long Gatelys Road, that is the project’s longest tunnel, the scheduled date for completing the benching work by consortium of Ferrovial and Gamuda Australia is early next year.
Considering that the heading excavation has reached around halfway on each of the 320m-long tubes, and benching work is due to be started and completed next year, Transport for NSW says the work is advancing well on the Shephards Lane Tunnel.
As the final section of the M1 Pacific Highway upgrade, the Coffs Harbour Bypass is jointly funded by the Australian and NSW governments, whereas each of the three tunnels will have two tubes, each designed to carry two lanes of traffic, with space for cyclists.
