East Link
While we at Spire are passionate about built heritage, we also have more than twenty years of experience working on large infrastructure and construction projects.
Background
The Mullum Mullum & Melba tunnels are a 1.6 km long freeway tunnel system that travels under the environmentally sensitive Mullum Mullum valley in Melbourne’s Eastern suburbs. The tunnels were constructed in 2006 and service up to 115,000 vehicles a day.
Challenge
Both tunnels feature 45m high ventilation stacks at their entry and exit points. The stacks are lined with a fireproof vermiculite which posed a risk of debris falling onto the roadway below. Spire was contracted to design, supply and install a debris netting system that would capture falling materials without impacting on tunnel services. Installation works were logistically constrained, fitting in with scheduled tunnel and lane closures and being performed in tandem with existing night works.
Process
Spire sourced and supplied all materials including 5500m2 of debris netting, 2500m of cable, and 36,000 geo-stabilisation fixings along with sufficient staff, vehicles, and plant to allow two crews to work continuous night shifts and complete the installation without the need for any unscheduled lane or tunnel closures. To safely place supporting cable anchorages, Ground Penetrating Radar was utilised to locate PT cables which ran through the structurally vital concrete beams. The netting was required to be installed above the mechanical and electrical services to ensure the functionality of tunnel lighting and traffic monitoring equipment was maintained. EWPs were utilised to position the nets with pneumatic tools used to efficiently fix nets onto the catenary cables.
