FORT MYERS, Fla — As clean-up efforts continue after Hurricane Ian many are now looking to the future. A question many engineers and scientists are asking now is how to rebuild Southwest Florida stronger after the storm.
After Hurricane Andrew in 1992, Florida used the storm as launch pad to make major advances in wind load construction ever since. Those advances were seen firsthand during Hurricane Ian, with most of the newer construction fairing relatively well. An example of this was seen in Punta Gorda, which was rebuilt after Hurricane Charley. While there are strong building codes for hurricane wind loads, those same codes are lagging for the type of storm surge damage seen in Fort Myers Beach and the barrier islands.
“Most of the significant damage is from the storm surge,” said Dr. Ioannis Zisis, Extreme Event Institute at Florida International University. "There are a lot of examples that I have seen, where newer homes, they performed very, very well from a wind point of view, a wind design point of view, they suffered damage due to storm surge.”
Dr. Zisis was on the ground shortly after Ian, studying the damage. From what he saw, the building codes addressing wind appear to have made a difference.
“There is definitely a correlation between how we design buildings, the new buildings, and the damage observed,” said Dr. Zisis.
While building codes battling against wind are working, those codes against storm surge are still lagging. The problem with storm surge is building to resist forces of advancing water, especially when a cubic yard of water weighs a ton.
“So, you can use brute force about it and say I am going to fortify against it, including the wave effect which is a tall order,” said Dr. Michel Bruneau, State University of New York Distinguished Professor and engineer. “Or you can say we will let it go and run through the first floor as a sacrificial floor. Have partitions that will break through that don’t threaten the integrity of the structural system.”
Dr. Bruneau says for multistory construction that sacrificial floor can still be used for parking, and recreation, with the understanding that the floor could be lost.
“If the upper story can keep the integrity of its façade,” said Dr. Bruneau. “No damage to windows and doors, so the wind doesn’t get inside, water doesn’t get inside. There is no water penetration inside. If the floor can be properly tied down, which many of them seem to have had in the more recent construction. Then essentially that enclosure is protected.”
When it comes to lifting homes that is another option. Dr. Zisis says that window load underneath the structure is something that the American Society of Civil Engineers is starting to set standards for.
“But now if we elevated, what is happening underneath,” said Dr. Zisis. “That is actually a recent addition to the ASCE7 standard, and now it includes loads, recommended design guidelines for elevated homes.”
And now as we rebuild, Dr. Bruneau says we all need to ask ourselves what level of risk we are willing to take ahead of the next hurricane.
“It’s not a question of if. It is a question of when,” said Dr. Bruneau. “And living there is assuming that risk. And having for example an elevated first floor, where you accept when the hurricane comes onshore, water will wash through the building and take whatever is there, is part of assuming the risk. You ask yourself the question, can I live with it? If the answer is yes, then you are already ahead of the game.”