Reports Look at Design, Corrosion in FL Collapse


Months after part of Champlain Towers South, in Surfside, Florida, collapsed killing 98 people, an investigation is ongoing surrounding what actually caused the collapse and how it unfolded. While it’s clear the collapse started at the pool deck area, what’s unclear is what accumulated to cause such a failure and how that failure compounded in the size of collapse that occurred.

A recent report form the Miami Herald has brought to light that the 12-story condominium tower had had multiple, extensive structural flaws present since the beginning of the building’s life—about 40 years.

Reportedly, the plans that came from a firm that no longer exists specified structural columns that were too narrow to accommodate the necessary amount of rebar to support the building. This meant that contractors had to choose between inadequately attaching floor slabs to supports, or putting extra steel into columns that were too small.

Most chose the latter, which is a recipe for air pockets that accelerate corrosion.

“The deck—which sat on skinny columns to maximize parking space below—was barely designed with enough strength to support a pool party, much less the layers of pavers and standing water that loaded it down over the decades,” the report says.

“While original design flaws alone were unlikely to have initiated the collapse that happened 40 years after construction, engineers consulted by the Herald said the deficiencies, in combination with concrete deterioration, could have been the difference between a single floor caving in and the kind of progressive collapse that killed 98 people.”

Among the speculation that’s looking at how a partial collapse of a patio could have part down part of a 12-story building, the Washington Post brought together engineers, construction plans and a computer simulation to come to two main scenarios.

First, if the deck initially collapsed where it joined the building’s facade, that could have overloaded the already-thin columns, causing them to buckle. Second, if the deck remained attached to the columns as it kept collapsing, that would have caused the tugging and twisting on the columns and the surrounding beams, causing them to fall.

Regardless of the final cause, building codes and inspections are already being reformed—with some Miami engineers saying that they have been evaluating 30-50 properties a week.

Inspection Spark

Last month, in Miami-Dade County, where the municipality is currently undergoing its 40-year recertification process, officials reportedly displaced hundreds of apartment building residents over safety concerns since the collapse.

According to Miami’s Local 10 News, the collapse caused a ripple effect among residents in condominium buildings who already had maintenance concerns. After many calls and demands for property inspections, some concerns were deemed unfounded and others led to the evacuations.

For example, about 300 residents at Crestview Towers at North Miami Beach were evacuated after officials found a Jan. 11 engineers’ report that warned of safety concerns. A two-story building in South Beach was also evacuated after a flooring system failure and excessive deflection of an exterior wall was found.

Moreover, the collapse in Miami led to structural and inspection concerns throughout the country. Most notably, it renewed worries about San Francisco’s leaning (and sinking) Millennium Tower, forcing professionals to step in and dispel concern.

Khalid Mosalam, a professor of structural engineering at UC Berkeley, went on the record and pointed to the differences in climate between Miami and San Francisco, as well as the age of the buildings and the differences between high- and mid-rise structures, to name a few.

However, there’s no denying that the Millennium Tower needs monitored, particularly as it undergoes its $100 million “fix,” which is slated to be completed next year.


Tagged categories: Accidents; Corrosion; Fatalities; Good Technical Practice; Health and safety; NA; North America; Safety

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