Investigators from the National Institute of Standards and Technology (NIST) say they have found no evidence of underground voids on the site of the Champlain Towers South collapse, according to a new NIST report.
The team of investigators have studied the site’s subsurface conditions to determine if sinkholes or excessive settling of the pile foundations might have caused the collapse. They have found no such evidence to support that potential cause.
Preliminary evaluation of data indicates about one quarter of an inch or less of settling in the pile foundations supporting the pool deck structure and basement. This would have had minimal impact on the pool deck structure, NIST says.
“Understanding exactly what caused this collapse is taking meticulous investigation and the collection of copious amounts of evidence and information,” said Joannie Chin, director of NIST’s Engineering Laboratory. “Our team members are dedicated to unraveling the complexities of this tragic event, and their rigorous research and analysis will not only help us understand the likely technical cause of the collapse but will improve the safety of our communities.”
The team’s preliminary evaluation of physical and historical evidence found that the pool deck construction deviated from design requirements. Specifically, the number of slab reinforcing bars centered over vertical columns was inadequate, and the reinforcing bars in the top of the slab in the vicinity of the columns were spaced farther apart than the design required, according to investigators. These deviations weakened the slab-column connections, they said.
NIST expects technical work on the investigation to be substantially completed in late June 2024 and aims to release a report with findings and recommendations in late June 2025.
Related Stories
| Mar 16, 2012
Stego embarks on HPD Pilot Program
Vapor barrier manufacturer strives to provide better green choices to designers and builders.
| Mar 16, 2012
Marvin Windows and Doors accepting entries for fourth-annual myMarvin Architect’s Challenge
Architects in U.S. and abroad offered the chance to showcase their very best work.
| Mar 14, 2012
Hearing to decide fate of unfinished Harmon in Las Vegas under way
The testimony began with CityCenter consulting engineer Chukwuma Ekwueme methodically showing photo after photo of parts of the Harmon, where he and his team had chipped away the concrete pillars and beams to examine the steel reinforcing bars inside.
| Mar 14, 2012
Firestone names 2012 Master Contractor Award Winners
Annual award acknowledges industry’s top roofing professionals.
| Mar 14, 2012
Plans for San Francisco's tallest building revamped
The glassy white high-rise would be 60 stories and 1,070 feet tall with an entrance at First and Mission streets.
| Mar 14, 2012
Hyatt joins Thornton Tomasetti as VP in Chicago
A forensic specialist, Hyatt has more than 10 years of experience performing investigations of structural failures throughout the U.S.
| Mar 14, 2012
Tsoi/Kobus and Centerbrook to design Jackson Laboratory facility in Farmington, Conn.
Building will house research into personalized, gene-based cancer screening and treatment.
| Mar 13, 2012
China's high-speed building boom
A 30-story hotel in Changsha went up in two weeks. Some question the safety in that, but the builder defends its methods.
| Mar 13, 2012
Commercial glazer Harmon expanding into Texas
Company expanding into the Texas market with a new office in Dallas and a satellite facility in Austin.
| Mar 13, 2012
Worker office space to drop below 100-sf in five years
The average for all companies for square feet per worker in 2017 will be 151 sf, compared to 176 sf, and 225 sf in 2010.
