Bridges

The Glenferrie Road bridge is located over Gardiners Creek in Hawthorn, Victoria and was constructed in 1891comprising three masonry arch spans with a total length of approximately 25 meters. The bridge was subsequently widened in 1921 by John Monash (later Sir) with a then highly innovative reinforced cast in situ concrete T-beam structure to facilitate the expansion of the electric tram network.

As a part of an ongoing overall strategic plan to improve tram access to the Victorian Road network, the Victorian Department of Transport engaged SMEC to undertake a detailed investigation of the bridge in 2021. This investigation included a detailed inspection, material testing and a load rating analysis of the historic bridge and determined that the structure had inadequate capacity to support various tram and road vehicles. SMEC were subsequently engaged to undertake the strengthening design of the masonry arch structure and the inter-connected reinforced concrete structural elements.

The strengthening of the arch involved the removal of the original bridge backfill and replacement with a flowable cement stabilised sand requiring in critical temporary staging criteria of the excavation works. The reinforced concrete spans were strengthening using external post-tensioning. The bridge strengthening was undertaken in early 2022 by Fulton Hogan and SRG Global.

As heavier road and rail loading is applied to the transport network in urban and brown-field locations it is expected that an increasing number of masonry arch bridges will be required to be strengthened in the near future. Lessons learnt during the design, analysis and construction staging may assist future strengthening design works on other similar bridges particularly because the structural behaviour of masonry arch bridges differs significantly from current new-bridge technology and the associated industry knowledge of typical new-bridges.