Bridges

At the height of recent strengthening of the West Gate Bridge, some 700 workers were engaged in various construction activities on, inside and underneath its steel and concrete spans, as well as at ground level. The deck of the bridge rises some 50 metres above the Yarra River which is the entry point to Australia’s busiest port. Safe and efficient access to the work fronts for people, materials and equipment was recognised from the outset as a key to the successful implementation of the project. The challenge was therefore to provide access systems to work sites on the bridge whilst it continued to carry 160,000 vehicles per day, spanned a busy commercial waterway and required wholesale strengthening works. A substantial temporary works program was duly undertaken to provide these access systems. Before the internal strengthening works in the steel spans started in earnest, existing access openings in their internal webs, diaphragms and top flanges were enlarged and new ones introduced, and internal walkways and landings installed to facilitate the movement of work crews and storage for materials. Access to the bridge from the ground was affected by temporary lifts that docked at specially designed platforms cantilevering off piers at the junctions between the steel bridge and the concrete approach spans. New and existing suspended work platforms and birdcage scaffolding were used to provide safe work areas from which the strengthening works to the external elements was carried out. Elevated crib facilities were located in the proximity of work fronts in order to minimise production lost by the workforce in transiting within the site. Legacy platforms, walkways, stairways, lifts and improved access openings will provide an enhanced access regime for the ongoing inspection and maintenance of the bridge. Upgraded security and surveillance systems will enable unauthorized access to the bridge and its environs to be strictly monitored and controlled.