Miami condo collapse: engineers explore demolition options
SURFSIDE, Florida – Engineers were evaluating demolition options on Friday the remaining part of a condominium building that has partially collapsed outside Miami last week, leaving 22 dead and 126 missing.
Miami-Dade County Mayor Daniella Levine Cava said she signed an emergency order to demolish the remaining part of the South Champlain Towers, once engineers approved the project, given the imminent threat to the structure for public health and safety.
There is no specific start date for the demolition,which would probably take “weeks,” Levine Cava said at a press briefing Friday night. Engineers meet regularly to determine what the demolition process would look like, and the top priority for officials remains search and rescue, she said.
âWe are very careful not to compromise our research, but we also know that the building itself presents risks. So we have to balance these things,â said Levine Cava, adding: âAs to where the demolition That is part of the calculation. There are many, many factors. There are many choices to be made. And all of this is being looked at by the engineers.
Concerns over the stability of the remaining structure prompted officials to suspend rescue efforts on Thursdayfor about 14 hours. Engineers on site identified a column that had shifted 6 to 12 inches and three cracks extending into the building, hovering over search and rescue teams sifting through large piles of rubble near its base.
With Newly formed hurricane Elsa heads for FloridaSurfside Mayor Charles Burkett said on Friday he wanted to speed up the eventual demolition of the remaining section. Burkett said rescue teams searched the building “from top to bottom, at least three times” and flew drones in and around the structure.
âIn most cases, preparing for a demolition takes a long time to test and make sure there is no asbestos. There is a list of things you do. But we have one. coming potential hurricane that’s going to tear it down for us, “Burkett said, addressing reporters after the press conference.
âAnd if that happens – and it just happens in the wrong direction – it could be a mess of immense proportions,â he said.
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Burkett said he raised the topic Thursday morning with Florida Governor Ron DeSantis. Burkett said if the United States can send men to the moon and launch missions to Mars, engineers should be able to demolish the damaged condominium structure within 24 hours if necessary.
âI think it would be better if we demolish it and push it in the direction we want – as opposed to the storm that demolishes it and pushes it in the direction it wants,â Burkett said.
Others feared that the demolition would take longer.
âIt can’t be before this storm,â Levine Cava said on Friday. “However, it is storm season. We know the building is unstable. We are going to demolish it, we just have to do it in the safest way possible.”
Scott Nachman, a structural specialist on FEMA’s search and rescue incident support team, said Thursday it would take weeks to establish a “best-case scenario” demolition schedule.
Alpha Wrecking, a demolition contractor based in Pompano Beach, Fla., Was on site and did not immediately respond to USA TODAY’s request for comment.
Elsa should emerge off the coast of Cuba on Sunday evening or Monday morning – and southern Florida could experience tropical storm force winds on Sunday, Monday or Tuesday, said Robert Molleda, the meteorologist responsible for coordinating warnings with the National Weather on Friday Service in Miami.
Tropical Atlantic storms pack maximum sustained surface winds of 39 to 73 mph.
“There are a lot of uncertainties in the forecast: how they will evolve, how the storm will interact with the land areas that lie to the south,” Molleda said. “And that could affect not only the intensity or strength of the storm, but also the path it takes.”
Nancy Pashkoff, 55, who has lived in Florida for 35 years, said it was “heartbreaking” to watch the scene unfold in Surfside and that she could barely help but cry at work.
She has closely followed recent announcements of demolition considerations. “I’m afraid they’ll do it sooner than expected as the storms approach,” Pashkoff said.
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Engineers and demolition companies not directly involved in the planning were divided over how best to demolish the building. There are several common demolition methods, including a wrecking ball, implosion, or high arm reach that deconstructs the building from top to bottom.
Mehrdad Sasani, professor of civil and environmental engineering at Northeastern University in Boston, said he suspected authorities would choose to demolish the building by implosion given its height and size – a process that involves the strategic placement of charges to direct the fall of buildings. .
âIf they implode the building, they can control how it’s going to fall and divert it from where they’re looking,â said Tony Stern, president of Riteway Demolition in Sunrise, Florida. “They could put people under the building and make it implode without putting people on the job they’re looking for.”
John Wallace, professor of structural engineering at the University of California, Los Angeles, said he suspected demolition would be unlikely until the search and rescue was completed. Any vibration associated with the tower collapse could impact the existing rubble pile, making it compact and tightening voids, he said.
Earlier this week, Miami-Dade Deputy Fire Chief Ray Jadallah said teams had identified additional voids in the rubble where residents could be located, but there is no evidence anyone is inside.
Once officials move into the salvage phase, it would make sense to demolish the remaining part of the building before completing the salvage efforts, Wallace said.
âIt will of course not be an easy decision. But removing debris from the existing rubble pile has the potential to destabilize the remaining and standing part of the building, and, even with very close surveillance, it is a challenge and not without significant risk, âhe said.
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Joshua Galanter, project coordinator at Thunder Demolition Inc. in Miami, said it typically takes months of engineering, preparation and assembly of explosives on the main support columns for a controlled implosion.
“They can bypass the usual planning and approval that these projects involve as it is a special emergency circumstance. But I would find it highly unlikely that the remaining structure would fall in the next 30 to 60 days,” he said. declared Galanter.
Abi Aghayere, an engineering professor at Drexel University, said he suspected authorities might choose to mechanically demolish the building. Using a wrecking ball would pose a great risk to surrounding buildings, and the vibration of an implosion could disrupt or crack other buildings as well, he said.
âThe way the structure collapsed on itself is what implosion tends to do. That way the debris field is confined, not scattered all over the place. But when you do that, d ‘other buildings may be affected,’ Aghayere said. .
A resort complex and condominium tower line the Champlain Towers property to the north and south, respectively, and bustling Collins Avenue sits just to the west. Succeeding in an implosion demolition in time would require engineers to inspect nearby buildings to determine the potential impact of the explosion, he said.
The method might also appear callous to those bereaved and whose loved ones have yet to be found, Aghayere said.
âWe have, really, one method left, where you have a long-reach, long-reach excavator that tends to take the structure apart piece by piece,â he said.
Even this method presents risks, he said, if the building then becomes unstable and falls.
“They must be careful in choosing which method will be used, taking into account the families who have lost loved ones in this building,” Aghayere said.
Contribution: Katherine Lewin, Jacksonville.com. Hauck reported from Chicago.
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