Surfside Collapse Notes
Engineer Warned of ‘Major Structural Damage’ at Florida Condo Complex
https://www.nytimes.com/2021/06/26/us/miami-building-collapse-investigation.html
The engineer's report on crumbling concrete is important but worth noting the original construction drawings released by Surfside gov show a lack of lateral bracing (shear walls) in the east-west direction, provided only in the north-south direction.
The break line in the collapse occurred along-side the western shear wall seen exposed adjoining the elevator-stair shaft. Floor slabs pulled away from the shear wall in the collapse.
The break also passed under a rooftop air-conditioning system mounted on steel beam dunnage. This system is larger and heavier than the single smaller units serving each apartment (apt numbers can be seen on the smaller units).
The original drawings also show the building foundation piles and pile caps, reinforcing bar layout and details. Pretty conventional in design and likely fits the standard of the area and building type due to the experience of the design architect and engineers.
If unexpected erosion occurred then that threat could apply to other buildings along the beach.
The original drawings of the "sister" condo to the north are nearly identical to those of the collapsed condo, though one bay shorter in E-W direction, with similar shear walls. So it definitely is a candidate for close study of vulnerability, perhaps to be vacated in the meantime.
However, subsoil conditions can be quite different even in close-by situations, so a review of the original soil reports is essential.
Disaster lessons learned to be applicable worldwide if, big if, not ignored.