A key component of Australia’s biggest public transport infrastructure project—Sydney’s $6.3-billion Metro North West—is the subject of a critical and detailed technical report describing how an elevated viaduct span failed at a stitch joint between two precast segments during construction last September. Project officials say the affected span, which did not suffer a progressive collapse, has since been removed and its replacement fast-tracked to avoid further delays. Little additional detail was provided.
The so-called Skytrain section is one of 115 spans being constructed using the precast segmental span-by-span method, erecting a series of precast box-girder segments supported by an overhead gantry and then stressed longitudinally.