On December 8, 2016, an office building in Boulder housing two local high-tech firms had to be evacuated after the partial collapse of the second floor due to a beam whose structural integrity had been negatively impacted. Nearly 280 people were temporarily relocated until repairs could be made.
But before repairs can be made, someone has to figure out what went wrong, and how best to fix it. As is often the case with forensic building assessments, these things can take time.
Seven weeks after the collapse, building owners and tenants alike are still awaiting further information. The Daily Camera’s Jerd Smith says that the cause of the failure remains a mystery:
Dave Thacker, chief building officer for Boulder, said the city is waiting for a forensic engineering report to be completed before determining what if any citations might be issued and what corrective actions might need to be taken. In the meantime, it has issued permits to allow for initial inspections, creation of a “safe passage” for construction workers, the shoring of the building’s foundation and the floor’s repair…
Such structural failures in commercial buildings are “unusual,” Thacker said. Among the theories under discussion include a weakening of the building’s foundation, due to the 2013 floods or a below-ground water leak, but no one has ruled out other causes as well, he said.
According to a preliminary investigation of the site, a connection tying a massive steel beam to a metal plate embedded in a concrete column sheared off. The beam supported the second floor. What caused the beam connection to fail is unclear.