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
| Apr 24, 2012
Roofing Supply Group acquired by Clayton, Dubilier & Rice
RSG provides a complete offering of residential and commercial roofing materials and related supplies.
| Apr 24, 2012
McLennan named Ashoka Fellow
McLennan was recognized for his work on the Living Building Challenge.
| Apr 24, 2012
AECOM design and engineering team realizes NASA vision for Sustainability Base
LEED Platinum facility opens at NASA Ames Research Center at California’s Moffett Field.
| Apr 23, 2012
Vegas’ CityCenter called financial ‘black hole’
Two and a half years ago, stockholders filed six lawsuits after the stock price fell from $99.75 on Oct. 9, 2007, to $1.89 on March 5, 2009. Bondholders sued over similar steep losses.
| Apr 23, 2012
Innovative engineering behind BIG’s Vancouver Tower
Buro Happold’s structural design supports the top-heavy, complex building in a high seismic zone; engineers are using BIM technology to design a concrete structure with post-tensioned walls.
| Apr 23, 2012
AAMA releases updated specification for anodized aluminum
AAMA 611-12 describes test procedures and requirements for high performance (Class I) and commercial (Class II) architectural quality aluminum oxide coatings applied to aluminum extrusions and panels for architectural products.
| Apr 23, 2012
Thornton Tomasetti project wins AISC Merit Award
Thornton Tomasetti provided structural design services through construction administration to architect HOK for the 1.6-million-sf tower and tiara structure, which comprises 15 steel tube arches spanning approximately 158 feet horizontally and 130 feet vertically from the top of the main building roof.
| Apr 23, 2012
Construction underway on City Winery Chicago
The Building Team is maintaining the old brick and timber construction, while adding 5,000-sf of new construction in the form of a two-story addition within the site’s existing courtyard.
| Apr 20, 2012
McCarthy completes Santa Barbara Cottage Hospital Replacement Facility
The new hospital’s architectural design combines traditional Santa Barbara Spanish colonial architecture with 21st century medical conveniences highlighted by a therapeutic and sustainable atmosphere.
