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
| Nov 16, 2010
Calculating office building performance? Yep, there’s an app for that
123 Zero build is a free tool for calculating the performance of a market-ready carbon-neutral office building design. The app estimates the discounted payback for constructing a zero emissions office building in any U.S. location, including the investment needed for photovoltaics to offset annual carbon emissions, payback calculations, estimated first costs for a highly energy efficient building, photovoltaic costs, discount rates, and user-specified fuel escalation rates.
| Nov 16, 2010
CityCenter’s new Harmon Hotel targeted for demolition
MGM Resorts officials want to demolish the unopened 27-story Harmon Hotel—one of the main components of its brand new $8.5 billion CityCenter development in Las Vegas. In 2008, inspectors found structural work on the Harmon didn’t match building plans submitted to the county, with construction issues focused on improperly placed steel reinforcing bar. In January 2009, MGM scrapped the building’s 200 condo units on the upper floors and stopped the tower at 27 stories, focusing on the Harmon having just 400 hotel rooms. With the Lord Norman Foster-designed building mired in litigation, construction has since been halted on the interior, and the blue-glass tower is essentially a 27-story empty shell.
| Nov 16, 2010
Where can your firm beat the recession? Try any of these 10 places
Wondering where condos and rental apartments will be needed? Where companies are looking to rent office space? Where people will need hotel rooms, retail stores, and restaurants? Newsweek compiled a list of the 10 American cities best situated for economic recovery. The cities fall into three basic groups: Texas, the New Silicon Valleys, and the Heartland Honeys. Welcome to the recovery.
| Nov 16, 2010
Landscape architecture challenges Andrés Duany’s Congress for New Urbanism
Andrés Duany, founder of the Congress for the New Urbanism, adopted the ideas, vision, and values of the early 20th Century landscape architects/planners John Nolen and Frederick Law Olmsted, Jr., to launch a movement that led to more than 300 new towns, regional plans, and community revitalization project commissions for his firm. However, now that there’s a societal buyer’s remorse about New Urbanism, Duany is coming up against a movement that sees landscape architecture—not architecture—as the design medium more capable of organizing the city and enhancing the urban experience.
| Nov 16, 2010
NFRC approves technical procedures for attachment product ratings
The NFRC Board of Directors has approved technical procedures for the development of U-factor, solar heat gain coefficient (SHGC), and visible transmittance (VT) ratings for co-planar interior and exterior attachment products. The new procedures, approved by unanimous voice vote last week at NFRC’s Fall Membership Meeting in San Francisco, will add co-planar attachments such as blinds and shades to the group’s existing portfolio of windows, doors, skylights, curtain walls, and window film.
| Nov 15, 2010
Gilbane to acquire W.G. Mills, Inc.
Rhode Island-based Gilbane Building Company announced plans to acquire W.G. Mills, Inc., a construction management firm with operations based in Florida. The acquisition will dramatically strengthen Gilbane’s position in Florida’s growing market and complement its already established presence in the southeast.
| Nov 11, 2010
Saint-Gobain to make $80 million investment in SAGE Electrochromics
Saint-Gobain, one of the world’s largest glass and construction material manufacturers, is making a strategic equity investment in SAGE Electrochromics to make electronically tintable “dynamic glass” an affordable, mass-market product, ushering in a new era of energy-saving buildings.
| Nov 11, 2010
Saint-Gobain to make $80 million investment in SAGE Electrochromics
Saint-Gobain, one of the world’s largest glass and construction material manufacturers, is making a strategic equity investment in SAGE Electrochromics to make electronically tintable “dynamic glass” an affordable, mass-market product, ushering in a new era of energy-saving buildings.
