Let’s start out with the obvious. Most apartment buildings do not collapse unless there is an external force such as a tornado, hurricane, or water surge. The rule of thumb is that if the building survives its construction phase, it will usually stand. There are many reasons for this:
1. Engineering calculations have many safety factors. Structural systems generally are not marginally designed.
2. Modern structural design in the US is good with local building inspections giving a building under construction many safety checks.
3. A building usually feels the most stress during its construction phase because it endures unusual loads during the construction which it will not feel once it is completed. A case in point was the collapse of one of Miami Dade College’s parking garages during its construction phase.
4. Concrete structures are designed for the concrete to give way and crack so that the issues with a building are obvious before the steel gives way and the building collapses.
5. Most of the time when issues are identified, they are dealt with in an appropriate fashion and in a timely manner.
6. Most buildings are used for the purpose for which they were built.
In speaking to a structural engineer who was involved with the Surfside building collapse after the catastrophe, she thought the main reason why the building collapsed was not due to poor maintenance, but rather to the additional weight which was put on the pool area when they remodeled it, the original poor structural design, and possibly the vibrations from the construction of the building next door.
Work without a permit is a serious issue in Miami. People continuously do work without permits, work without the proper professionals – without architects, mechanical, electrical, and structural engineers. All kinds of things can go wrong when you don’t know what you are doing. As Miami architects, we see this all the time. If you do not know if an interior partition is a bearing partition, and it is likely to be one, if the residence was built prior to 1960, do not remove it. You could have the roof collapse on you!
During my working life as an architect, in addition to the Surfside building, I only recall these two incidents below of structures that were completed but failed.
A walkway at the Hyatt Regency in Kansas City collapsed in 1981, killing 114 people. This was an unusual case. People were there for a convention and the skywalk was packed with partygoers while people on the ground floor were dancing. A year after the building opened the 4th-floor skywalk collapsed. There was a change by the general contractor on how the skywalk was attached and apparently nobody checked the shop drawings. So, the combination of too many people on the skywalk with a poor design caused the catastrophe.
In Genoa, Italy, the 1967 Morandi Bridge collapsed in 2012 killing 43 people. In this case, the people thought to be liable were Autostrade and Spea, who escaped a trial due to an out-of-court settlement with the public prosecutor's office. The two companies provided a payment of 29 million euros to the state. Autostrade per l'Italia (ASPI), which runs much of Italy's motorway network. and Spea, the engineering company, were thought to have been responsible because they failed to keep up with the maintenance of the bridge.
Post-tensioned structures are particularly vulnerable if water gets to the tension cables. I see a lot of work around town where balconies are being repaired. I assume that this work has to do with the tension cables.
I remember many years ago when Brickell Harbour Condominium on SE 15th Road had structural issues, the fire department gave the residents a couple of hours to evacuate the building. It was a blessing that no one was hurt and after they were able to make the necessary repairs, the building was inhabited again.
So, what can you learn from this article:
· Do not do work without a permit, particularly if you do not have construction knowledge.
· Do not add additional loading to a structure without the review of an architect and structural engineer.
· Make sure if you live in a condo or apartment building that the owners maintain the building and have reserves for any repairs that may be needed in the future.
· Make sure you review all maintenance records before buying a condominium unit.
· And, lastly, you don’t have to live in fear if you do the above. Most buildings do not fall down!