Lessons from the Champlain Towers South Collapse

Lessons from the Champlain Towers South Collapse​

The tragic collapse of the Champlain Towers South condominium in Surfside, Florida, on June 24, 2021, which resulted in the loss of 98 lives, has highlighted critical issues in building safety and maintenance practices. Detailed investigations by the National Institute of Standards and Technology (NIST) and the engineering firm Wiss, Janney, Elstner Associates (WJE) have uncovered significant findings that underscore the necessity for rigorous adherence to building codes and routine maintenance by condo associations.

Key Findings from the Investigations​

Initial Failure Point: The WJE engineers, who were hired by the court-appointed receiver for the condo association, and the NIST team both identified the pool deck as the initial failure site. According to WJE, the first failure likely occurred at columns L-13.1 and K-13.1 due to "punching shear" failures. This phenomenon occurs when a column punches through a slab, which in this case was exacerbated by the deck's inadequate reinforcement and construction deviations from the original design.

Detailed Analysis by WJE: In their recently released webinar, WJE engineers provided a detailed analysis:

• Construction Flaws: The construction did not comply with building codes, particularly in the reinforcement of concrete slabs and columns. The number of reinforcing bars was insufficient, and their spacing was not as per the design requirements, significantly weakening the structural integrity.
• Environmental Degradation: Over the building's 40-year lifespan, environmental factors, such as water infiltration, contributed to the degradation of critical structural components. Photos taken in November 2020 showed water entering along the face of column L-13.1, indicating distress related to punching shear.
• Sequence of Events: The WJE team concluded that the initial failure at column K-13.1, followed by nearby columns, led to a large section of the deck collapsing around 1:15 a.m. This instability caused the towers to the north and east to collapse about seven minutes later.

Corroborating NIST's Findings: NIST's investigation aligns with WJE's conclusions, pointing to several contributing factors:

• Design Flaws: The building had design flaws that overloaded certain areas.
• Construction Issues: Construction did not meet the original building codes, and subsequent modifications over the years worsened the situation.
• Material Testing: NIST's testing revealed that while the concrete generally met design specifications, the construction deviations were critical.

Importance of Routine Maintenance​

This catastrophic event underscores the crucial role of regular inspections and maintenance in ensuring structural safety. Condo associations must prioritize and invest in ongoing maintenance to address potential issues before they become catastrophic failures. The collapse of Champlain Towers South serves as a stark reminder of the consequences of neglect and the need for proactive measures.

Florida's Milestone Inspection Program​

In response to this tragedy, Florida has implemented the Milestone Inspection Program. This program mandates periodic structural inspections of older buildings to identify and rectify potential safety issues. The goal is to prevent such disasters by ensuring early detection and timely remediation of structural deficiencies. The program includes:

• Mandatory Inspections: Buildings older than 30 years (or 25 years if within three miles of the coast) must undergo inspections every ten years.
• Detailed Reporting: Engineers must provide detailed reports on the structural condition and recommend necessary repairs.
• Compliance and Enforcement: Condo associations are required to comply with these inspections, and failure to do so can result in penalties and mandatory evacuations for unsafe structures.

Conclusion​

The collapse of Champlain Towers South is a somber reminder of the importance of structural integrity, rigorous construction practices, and routine maintenance. The findings from NIST and WJE highlight the need for adherence to building codes and proactive maintenance strategies. Condo associations must take these lessons to heart, ensuring that their buildings are safe and secure for all residents.

By implementing and adhering to programs like Florida's Milestone Inspection Program, we can work towards preventing future tragedies and safeguarding the built environment. Regular maintenance and inspections are not just regulatory requirements but essential practices to protect lives and property.

 

[Yankee Chronicler]

Some while back I watched a video presentation by WJE of their investigation findings. It was sobering. If I am remembering the details correctly, there should be no surprise that the building collapsed -- the only surprise should be that it stayed up as long as it did. It was under-designed from the git-go. It left me wondering about the twin, which is two buildings away from the one that collapsed.

I've gotten any number of people "upset" (to use a socially acceptable term) with me in the three years I've been in my present job, for questioning the structural designs of building I'm reviewing for permit. The sobering thing is, I'm not a licensed PE, yet every single one I questioned ultimately had to be redesigned after review for structural adequacy. If I just accepted the structural drawings because they had an engineer's seal and signature -- the buildings might have stood up for 50 years, or they might not. There's no way to know, since in the end they weren't built according to the plans I questioned.

This isn't trying to toot my own horn. I make mistakes, too. Whenever possible, I try to err in the direction of safety. The point is that we've all (or most of us) been around construction a long time. If something doesn't look or feel right -- trust your gut and at least question it. As a licensed design professional myself, I know too well that an architect's or engineer's seal and signature doesn't in any way guarantee that the plans meet even the most minimum of building code requirements. We don't get paid to rubber stamp a set of construction documents that have a seal and signature. We get paid to review the documents enough to satisfy ourselves that the drawings comply with the codes.