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Importance of back-propping

Last updated July 29, 2026

A construction site at Marcus Clarke St, Canberra, Australia. 27-Oct-2008

The completed slab pour at a Canberra site, formwork and reinforcement starters in place, with the deep excavation fenced off in orange below
The same slab after the back-propping below it gave way: the edge has dropped and folded into the excavation, taking the formwork and scaffold with it
Close view of the collapse - scaffold tube, formwork sheets and reinforcement mesh tangled in the bottom of the excavation, with workers looking on from the level above