Steel girder sections that deflected during construction of an Edmonton, Alberta, bridge are being shipped back to the project's locally based fabricator and erector, Supreme Steel.
A structural engineering team will then decide whether the girder sections on the bridge at 102 Avenue over Groat Road must be repaired or replaced entirely, city transportation officials said in a press statement.
Sections of four girders suddenly underwent torsional lateral buckling, three by several feet, in the early morning hours of March 16, after they had been hoisted into place to complete the central span.
Photos and video of the twisted steel on the $32-million bridge project made headlines in Canada and generated lively debate as to the cause.
Edmonton officials hired Vancouver-based bridge engineer Buckland & Taylor, a unit of Denmark-based COWI, to examine the span and the girders.
While girders 1, 2 and 3 were not damaged, a review by city officials and the project’s contractors has determined that girders 4, 5, and 6 had to be removed, Edmonton officials said in the statement. While undamaged, girder 7 will be removed in order to access the other three girder sections.
Groat Road, a busy commuter thoroughfare into downtown Edmonton that runs under the bridge, will be closed over two weekends this month as the girders are removed.
The project's contracting team includes the Los Angeles-based engineer AECOM and Calgary-based Graham Construction.
The new bridge had an initial budget of $32 million. The span stretches roughly 100 meters over Groat Road; the banks on each end were stabilized with soil nails. The bolted, three-section girders are roughly 4.2 m deep at their ends, which are encased in concrete abutments.