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Boise, Idaho Steel Portal Frame Collapse
Unsure how broadcast this was back in the UK, but there was a recent significant structural collapse in Boise, Idaho. A steel portal frame under construction collapsed under what appeared to be high winds, resulting in the death of three workers and nine others injured.
The investigation into why the structure collapsed is still ongoing by OSHA, but the information put out so far appears to indicate that high winds, combined with a lack of installed cross-bracing, resulted in the collapse of the structure at the centre, bringing down a supporting crane during a lift.
Whilst a tragedy, I think this can provide some crucial guidance as to the dangers of ignoring methodology, underestimating environmental loads and temporary loads. I’m sure in the finished design that the wind load was dealt with properly by a sufficient bracing system, but it seems that from the trickle of information being released from the site that it was overlooked during the actual method of works. From a recent news article, an individual said “Wind picked up and they were scrambling to install guy wires and cross braces before the collapse. Said the building was making all sort of nasty noises then it was a massive all at once failure.” Even if this was considered in design, the H&S plan for operation was either not substantive enough, or ignored, for the construction to still be operating in high wind. For the site I was on, during the erection of the steel frame, if high winds were recorded, any work on the frame would pause until the wind subsides. This is certainly evident in the UK, with the BCSA (Pub No. 39/05) publishing a guide specifically on the erection of steel frames in windy conditions. If there had been no workers on site during these high winds, it still would have been an expensive collapse, but at least no loss of life would have occurred.
Usurpingly, the principal contractor, Big D Builders, have had a history of safety violations and fines from OSHA. Whether this is just a coincidence or a critical link, I am sure the OSHA report will say.
Certainly relevant for Ex STEEL and the temporary works element for future courses. A morbid lesson that can teach us the importance of H&S plans on site, construction methodology, and most importantly, how temporary works should support a construction to prevent unnecessary deaths.
Further articles on the collapse:
https://www.idahostatesman.com/news/local/community/boise/article284954822.html
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