Toowoomba Range Clearance Upgrade
About the project
Scope
Drainage works including headwalls, insitu custom pits, stormwater, reinforced concrete pipes and reinforced concrete box culverts, as well as rediverting drainage swales, and construction of outlet drainage outside the tunnels
Lowering 11 tunnels by approximately 1 metre, eight with track slabs and three featuring ballast with sleepers
Construction and installation of 477 track slabs involving 4236 Delkor units
Installation of over 1300 soil nails to reinforce the concrete walls after excavation
Installation of 12,300 tonnes of ballast
7800m3 of profiled earthworks within the tunnels
Construction of access tracks
Outcomes
The 11 tunnels were heritage listed and approximately 100 years old, requiring unique excavation methods to ensure the integrity of the structures during construction. The project team worked through a range of methodologies to ensure the effective excavation of the rock within each of the tunnels. The selected models included using rock breakers and profiling machines depending on which rock conditions were present. This approach and the use of non-conventional methods of excavation were extremely effective, resulting in no damage to the heritage listed structures.
The successful completion of this highly complex and time critical project required fastidious planning including providing all detail regarding construction, methodology, equipment and resourcing requirements four to six weeks prior to pre-planned track closures. BMD’s project team ultimately released the tracks back to the client on time and with no lost time injuries.