Dive Brief:

• New details came to light Thursday regarding what caused the collapse of the Champlain Towers South building in Surfside, Florida, that killed 98 people in June 2021.
• A report from the National Institute of Standards and Technology noted that the construction of the condominium’s pool deck deviated from design requirements and that the number of slab reinforcing bars centered over vertical columns was inadequate.
• The NIST team also found that the reinforcing bars in the top of the slab in the vicinity of the columns were spaced farther apart than the design required. These deviations weakened the slab-column connections, the report said.

Dive Insight:

Federal investigators have been studying subsurface conditions of the site to determine if sinkholes or excessive settling of the pile foundations might have contributed to the collapse. The investigation did not reveal evidence of sinkholes that could have created voids under the foundation, the report said.

“The preliminary evaluation of the data collected indicates that approximately one-quarter of an inch or less of settling occurred in the pile foundations supporting the pool deck structure and basement, which would have had minimal impact on the pool deck structure,” according to the NIST.

To date the team has extracted more than 300 concrete cores and rebar samples and has begun materials testing. So far, the average tested concrete strength for various structural elements such as slabs and columns exceeds the specified design strength for those elements. The team will continue to conduct strength tests and detailed statistical analysis before drawing general conclusions, NIST said.

Investigators have also made significant progress on the use of computer models for simulating the collapse initiation and progression, and said they hope to have a final report by June 2025.

Late last month, Surfside officials approved developer DAMAC Properties’ plans for a new 12-story condominium to be built on the site of the collapse, according to NPR. Family members of those who died have objected to the plans, partly because they would place a memorial to the victims next to a loading dock.

The Dubai-based firm purchased the 2-acre beachfront property for nearly $120 million last August.