The $407.5 million duplication of the Southern Expressway was a key development of Adelaide’s north-south corridor to deliver an 18.5km multi-lane, two-way expressway between the suburbs Bedford Park and Old Noarlunga. McMahon Services were awarded the works to demolish the Glenthorne Path footbridge crossing the former single lane Expressway.
Scope of Work
Works comprised of the demolition of the Glenthorne Path footbridge for the Southern Expressway Duplication Project. Scope included protection of the Eastern Veloway underneath the Glenthorne Bridge, the eastern abutment and the eastern retaining wall. Demolished structures included handrails and fencing, bridge railing, bridge parapet barriers, reinforced concrete bridge deck, steel girders and bracings, and underbridge lighting.
Works were completed over a three-day period on a weekend to minimise disruption to traffic on the Expressway. Demolition of the bridge was achieved using 30t and 45t excavators with hammer attachments. Excavators were placed at each end of the bridge deck and systematically pulverised the bridge from the centre outwards. 620t of 300mm rubble base and geotech fabric placed on the road protected the pavements from falling demolition debris.
A 100t crane operating from the Expressway then removed the six steel bridge beams. Crane lift studies were developed and approved for the lifts.
Final works were the pulverisation of the eastern and western abutments including approach slabs. Demolished materials were recycled for use in the construction of the new carriageway.