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
| Dec 5, 2011
Summit Design+Build begins renovation of Chicago’s Esquire Theatre
The 33,000 square foot building will undergo an extensive structural remodel and core & shell build-out changing the building’s use from a movie theater to a high-end retail center.
| Dec 5, 2011
Fraser Brown MacKenna wins Green Gown Award
Working closely with staff at Queen Mary University of London, MEP Engineers Mott MacDonald, Cost Consultants Burnley Wilson Fish and main contractor Charter Construction, we developed a three-fold solution for the sustainable retrofit of the building.
| Dec 5, 2011
RJM Construction begins building Nova Classical Academy in St. Paul
As the general contractor, RJM is constructing the 94,000-sf building that will consolidate the St. Paul school’s two other locations.
| Dec 5, 2011
Gables Residential brings mixed-use building to Houston's Tanglewood area
The design integrates a detailed brick and masonry facade, acknowledging the soft pastel color palette of the surrounding Mediterranean heritage of Tanglewood.
| Dec 5, 2011
SchenkelShultz Architecture designs Dr. Phillips Charities Headquarters building in Orlando
The building incorporates sustainable architectural features, environmentally friendly building products, energy-efficient systems, and environmentally-sensitive construction practices.
| Dec 2, 2011
What are you waiting for? BD+C's 2012 40 Under 40 nominations are due Friday, Jan. 20
Nominate a colleague, peer, or even yourself. Applications available here.
| Dec 2, 2011
Legrand joins White House initiative to spur energy efficiency in commercial buildings
Company agrees to aggressive energy savings and reporting.
| Dec 2, 2011
Goody Clancy awarded Ohio State residential project
The project, which is focused on developing a vibrant on-campus community of learning for OSU undergraduates.
| Dec 1, 2011
Nauset Construction breaks ground on Massachusetts health care center
The $20 million project is scheduled to be completed by December 2012.
