Miami Condominium Collapse: Engineers Examine Demolition Choices

SURFSIDE – Engineers on Friday were reviewing options for demolishing the remaining portion of a condo building that partially collapsed outside of Miami last week, killing 20 people and missing 128.

Miami-Dade County’s Mayoress Daniella Levine Cava said officials had “a couple of meetings” Friday with engineers who meet “regularly” to determine what the process would be.

“We are continuing our assessment of all factors and the impact of the demolition of the building during the search and rescue operations is our top priority,” Levine Cava said at a press conference.

Concerns about the stability of the remaining portion of Champlain Towers South caused officials to temporarily suspend rescue operations Thursday after on-site engineers found a pillar in the building that had moved 15 to 12 inches and three cracks that expanded.

With the newly formed Hurricane Elsa hurtling towards Florida, Surfside’s Mayor Charles Burkett said Friday he wanted to hasten the possible demolition of the remaining section.

“In most cases, setting up for a demolition is a time-consuming attempt to make sure there is no asbestos. There’s a list of things you tear down for us, “Burkett told reporters after the press conference.

“And if that happens – and it just blows it the wrong way – it could be a mess of immense proportions,” he said.

Surfside death toll rises to 20:The 7-year-old daughter of a firefighter was killed in a condo collapse in Florida

Burkett said he raised the issue with Florida Governor Ron DeSantis Thursday morning. Burkett said if the US could 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.

“I think it would be better if we tear it down and slide it in the direction we want – as opposed to the storm tearing it down and pushing it in the direction we want,” said Burkett.

Others feared the demolition could take longer. Scott Nachman, structural specialist on the FEMA search and rescue support team, said Thursday it would take weeks to set a “best-case” timetable for the demolition.

Levine Cava said Friday the process could take “weeks”.

“We will proceed quickly with the decision-making process, but it will take some time before the demolition takes place,” said Levine Cava. “Demolition cannot happen overnight. In fact, it takes weeks to demolish a building.”

Alpha Wrecking, a Pompano Beach, Florida-based demolition company was there and did not immediately respond to USA TODAY’s request for comment.

Elsa is expected to appear off the coast of Cuba by Sunday evening or Monday morning – and South Florida could experience tropical storm winds on Sunday, Monday or Tuesday, said Robert Molleda, the meteorologist for warning coordination at the National Weather Service in Miami Friday.

Atlantic tropical storms pack maximum sustained surface winds of 39 to 73 miles per hour.

“The prediction is very uncertain: how it will develop, how the storm will interact with the land areas in our south,” said Molleda. “And that could not only affect the intensity or the strength of the storm, but also the distance it takes.”

Nancy Pashkoff, 55, who has lived in Florida for 35 years, said it was “heartbreaking” to see the scene unfold at Surfside and that she couldn’t stop herself from crying at work.

She has been closely following the recent announcements of demolition considerations. “I’m worried that if storms are approaching, they might do it earlier than planned,” said Pashkoff.

Engineers and demolition companies not directly involved in the planning agreed on the best way to dismantle the building. There are several common demolition methods, including a wrecking ball, implosion, or high arm-reach that disassembles the building from top to bottom.

Mehrdad Sasani, a professor of civil and environmental engineering at Northeastern University in Boston, said he suspected officials would implosion the building down because of its height and size – a process that involves the strategic placement of cargoes around the case to direct the building.

“If they implode the building, they can control the way it’s going to fall and steer it away from where they’re looking,” said Tony Stern, president of Riteway Demolition in Sunrise, Florida. “You could get people under the building and implode it without putting people on top of the pile where they’re looking.”

John Wallace, a professor of civil engineering at the University of California at Los Angeles, said he believed it would be unlikely to be demolished until the search and rescue is complete. Any vibration related to the tower’s collapse could affect the existing pile of rubble, compacting it and narrowing voids, he said.

Once officials move into the restoration phase, it would make sense to demolish the remaining portion of the building before the restoration work is completed, Wallace said.

“That will of course not be an easy decision. But removing debris from the existing pile of rubble has the potential to destabilize the remaining, standing portion of the building, and even with very close monitoring, it is challenging, not “without significant risk.”

Joshua Galanter, project coordinator at Thunder Demolition Inc. in Miami, said that controlled implosion typically requires months of construction, prep, and assembly work on the main support columns.

“You can bypass the usual planning and approval of these projects because this is a special emergency. However, I think it is very unlikely that the remaining structure will collapse within the next 30 to 60 days,” he said.

Abi Aghayere, an engineering engineer at Drexel University, said he suspected officials might mechanically tear down the building. Using a wrecking ball would put surrounding buildings at great risk, and the vibrations from an implosion could potentially disrupt or crack other buildings, he said.

“The way the structure fell on itself is the tendency to implosion. That way, the field of debris is limited and not scattered all over the place. But if you do, other buildings can be affected,” he said.

To get this done in time, engineers would have to inspect nearby buildings to determine the potential impact of the explosion, he said. The method could also seem insensitive to families and other bereaved, said Aghayere.

“We really only have one method left, which is to have a long-arm, high-reach demolition that tends to break down the structure bit by bit,” he said.

This method also carries risks if the building then becomes unstable and collapses.

“You need to be careful about the method you choose and take into account the families who have lost loved ones in this building,” said Aghayere.

Contributor: Katherine Lewin, Hauck reported from Chicago.

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