Could the increasing assault of king tides and sea level rise have contributed to Miami condo collapse?
Saltwater and brine-soaked air settle into the pores of coastal construction, growing a rusty crust around the steel skeletons that reinforce oceanfront structures. It weakens the bonds between metal and concrete creating cracks and crumbles in vulnerable areas. Some building experts wondered Thursday if that kind of environmental assault supercharged by climate change could have played a role in the catastrophic collapse at the 40-year-old Champlain Towers South Condo in Surfside, Fla.  Sea level rise does cause potential corrosion and if that was happening, its possible it could not handle the weight of the building, said Zhong-Ren Peng, professor and Director of University of Floridas International Center for Adaptation Planning and Design. I think this could be a wakeup call for coastal developments.  Sea level rise, the gurgle of more frequent king tide flooding, and changes in soil consistency or location are elements dealt with by any building on a barrier island. Collapsed Miami condo had been sinkinginto Earth as early as the 1990s, researchers say  Latest updates on the condo collapse: At least 4 people dead, 159 unaccounted for  And below the surface  beneath parking garages  the twice-daily pressure of the tides on groundwater could keep a buildings foundation wet and on an uneven footing. The invisible machinations that can weaken a buildings integrity  The Champlain Towers South Condo has a plump renourished beach and dune to assuage a direct ocean charge and is four blocks from Biscayne Bay. Still, Albert Slap, president of Boca Raton-based RiskFootprint, said it can be invisible machinations  the push and pull of tides on limestone bedrock  combined with rising seas that can weaken a buildings integrity. RiskFootprint provides assessments for private homeowners and business developments that includes looking at threats from sea level rise, king tides  so-called sunny day flooding  and storm surge. Even if when the building was built in 1981 the foundation was dry most of the time, with sea level rise pushing groundwater up to the surface, the foundation could be wet enough long enough to soften the concrete, Slap said. Many of these buildings with underground parking have sump pumps running and that means the foundation is in the water.  Related:Engineer who probed FIU bridge collapse to investigate Surfside condo  A 2019 analysis by the National Oceanic and Atmospheric Administration found that high tide flooding the previous year broke records at more than a dozen locations, including Miami and Cedar Key on the Gulf Coast. At the same time global sea-level rise is about 1 inch every eight years. Sea-level rise in South Florida  Between 2000 and 2017 alone, sea-level rise at the Key West tide gauge measured about 3.9 inches, according to the Southeast Regional Climate Change Compact's 2019 sea-level rise report. South Florida's coastal waters could jump 10 to 17 inches by 2040 and 21 to 54 inches by 2070 above the 2000 mean sea level in Key West. The long-term sea-level rise is predicted to be 40 to 136 inches by 2120, the report says. The compact stresses that South Florida's sea-level rise could be faster than the global rate because of a slowing of the Gulf Stream current. Heartbreaking imagescapture the Surfside building collapse and rescue efforts  Climate change can play a role, said Atorod Azizinamini, chair of Florida International Universitys College of Engineering. It can cause settlement of the ground with sea level rise, and corrosion.  Buildings can be designed to withstand anything anywhere. You can have a high rise building in the middle of the ocean, Azizinamini said. But in the 1980s, the subtle creep of rising seas was likely less of a concern. A Florida International University study on the building found that it had been sinking since the 1990s at a rate of about 2 millimeters a year. FIU Department of Earth and Environment Professor Shimon Wdowinski was lead author on a report published in Science Direct on subsidence  land sinking  in Miami Beach and Norfolk, VA. The report notes the Champlain only as a "12-story building." The main message now is we dont want to rush to conclusions, said Azizinamini. Let the investigation happen and we can learn from our mistakes.  Investigation into collapse could take months  Eugenio Santiago, a structural engineer and former chief building official at the Village of Key Biscayne, isnt convinced rising seas or wet concrete had anything to do with Thursdays collapse. He said the way the building pancaked makes him think it was the failure of a column holding up a slab of floor. When it fails, one slab punches through to the next in a chain reaction until it reaches the ground. If the building was undergoing roof work, as Surfside Mayor Charles Burkett said on NBCs Today show, its possible heavy materials could have been placed improperly, causing the failure. It would be very rare to have a building with that much corrosion and no one saw it, Santiago said about a link to saltwater and sea level rise. To have that kind of corrosive damage, someone would have said something or seen something.  At 40 years old, the building was undergoing a required recertification. Madasamy Arockiasamy, Director of the Center for Infrastructure and Constructed Facilities at Florida Atlantic University, said the settling noted by FIU could be one reason for the collapse. He doesnt believe climate change had a direct impact, instead agreeing with Santiago that it could have been caused by heavy equipment on the roof. Roofs are designed to hold a very specific amount of weight. He noted air conditioning units on Champlain's roof and said it would generally be built to withstand some light roof construction. The video shows the middle portion of the roof collapses followed by the sides, Arockiasamy said. More bending means you stress the concrete beyond its tensile capacity.  There are older buildings on the same barrier island with Surfside that have not suffered the kind of structural breakdown that happened at Champlain Towers, but Slap said buildings deal with geologic and environmental situations differently. Azizinamini agreed. "You can have two buildings next to each other, one made a mistake in design and the other didn't," he said. "It's natural for people to try to identify right away what happened, but that's not the scientific approach." Azizinamini said the investigation could take months with everything from corrosion to nearby construction analyzed for its potential role in the devastation. Kmiller@pbpost.com  @Kmillerweather