Why the house collapsed in Miami: while rescuers are looking for survivors, engineers are putting forward versions
On the night of June 24, a 12-story residential building collapsed in Surfside, Florida. 16 people died, another 147 are missing, and 35 were rescued. The authorities hope that some of the people could survive in the air pockets formed in the wreckage. They are searched for using dogs, sonar, drones and infrared scanning. In the meantime, the search continues, experts put forward theories of why the building could collapse. The edition told in more detail with the BBC.
Among the missing is the sister of the wife of the President of Paraguay.
The disaster occurred at approximately 01:30 local time. Following the collapse, a fire broke out.
The 12-story, 136-unit, reinforced concrete building called Champlain Towers South was erected in 1981.
The rescue operation continues, but there are already questions about the causes of the tragedy.
According to experts, there could be several of them, and they could act singly or in aggregate.
What the video showed
Judging by the footage from the surveillance camera from the neighboring house, it is clear that the building collapsed not overnight, but in stages.
The south-facing central section collapsed first, followed by the north wing three seconds later and the east wing five seconds later.
Experts who have studied the recording suggest that the collapse process began in the basement of the building, above which there was a swimming pool located in front of the central section.
One of the residents, Casey Stratton, was on the phone with her husband at the time of the disaster and managed to say: "Honey, the pool is failing."
Aerial photographs show that the pool and the adjacent courtyard collapsed into an underground parking lot.
In a technical inspection of the building in 2018, it was the pool that was identified as a place of concern.
What was said in the materials of the inspection
The audit recorded a major miscalculation made in the design of the building.
Engineer Frank Morabito, who carried out the inspection, noticed that the base of the pool did not have a slope for water drainage, and moisture accumulated in the waterproofing layer, and was there before evaporation.
He also wrote in his report that this waterproofing layer had reached the end of its useful life, due to which the concrete slab underneath was systematically damaged.
If everything is urgently replaced, concrete destruction will accelerate, he warned.
Also in his report, he mentioned numerous cracks in the load-bearing columns, ceilings and walls of the parking lot.
The report did not mention the immediate danger of collapse, but indicated that the necessary work must be done in due time.
In April 2021, the president of the apartment owners' association, Jae Vodnicki, in a letter to the tenants, said that the condition of the house had deteriorated compared to 2018, and asked to raise money for urgent repairs. He estimated its cost at $ 1,9 million.
By the time of the collapse, the roof was being repaired, but work in the basement of the building had not yet begun.
Could the weakening of reinforced concrete structures cause tragedy
Engineer Preg Batista, who has inspected several thousand homes in his career, believes it could.
“Houses along the coast are subject to what we call cracking,” he said.
“The reinforcement embedded in concrete, rusting, increases in volume, sometimes up to seven times. The concrete around it begins to crack, which decreases its strength. And if one column or overlap fails, everything develops further according to the domino principle, ”the expert explained.
In 1999, scientists at Florida International University found that local buildings were sinking at a rate of two millimeters a year.
The mobility of the soil could contribute to the destruction of concrete.
Professor Shimon Wdowinsky, who participated in that study, says that it included the now collapsed house, and although it did not focus on it, it marked it as one of the most vulnerable.
According to him, two millimeters a year is not very much.
You may be interested in: top New York news, stories of our immigrants and helpful tips about life in the Big Apple - read it all on ForumDaily New York.
“But we don’t know what has happened since then, whether the building continued to collapse and at what rate,” he said.
“Perhaps a critical threshold was reached beyond which the base of the building could no longer support the weight. But house construction is not my specialty, ”he said.
“We know that the collapsed house has been settling for decades. But this in itself could hardly have caused a catastrophe, ”he added.
Could a neighboring construction site have hurt
Some experts say the mobility of the soil may well have been enhanced by the construction of an 18-storey residential complex being carried out nearby.
In 2019, residents of Champlain Towers South complained of severe vibration, but were only advised to keep monitoring the situation.
Other buildings are also in danger
The Champlain Towers South was erected on a drained swamp.
Like it, most of the high-rise buildings on the coast are built on pile foundations, when reinforced concrete columns are driven into the ground, transferring the weight of the structure to the ground.
Not far from the collapsed building is an almost exact copy of it, Champlain Towers North.
Today, the occupants of these homes are demanding assurances that their homes are not subject to the same problems. City officials have already ordered additional checks to begin.
When exactly the reason will be known
Atorod Azizinamini, director of the School of Construction, Infrastructure and Sustainable Development at Florida International University, says the investigation will take time.
First, specialists will study in detail the design documentation, the progress of construction, which took place 40 years ago, samples of concrete and steel, and find out if any unusual incident preceded the disaster.
Then they will evaluate the possible scenarios and only then will they be able to say why the house collapsed after all.
Federal investigators are already working at the crash site. The wreckage is transported to a large warehouse for further examinations.
Why rescue operations take so long
Rescuing survivors is a delicate operation. Disassembling the debris too quickly could cause another collapse, and this endangers not only the rescuers, but also those who may be under the rubble.
Every careless movement can trigger a backlash. There is a small chance that the victims could get stuck in the crevices between the wreckage. Heavy equipment was used for the search, but it only increases the risk of new debris collapsing.
Rescuers work in difficult conditions for 12 hours a day: it is hot, dusty and stuffy on the ruins of the building. Also, the work is complicated by a fire that broke out under the rubble: because of the thick layer of smoke, it was difficult to navigate.
Rains and storms further complicated the search operation. Due to the thunderstorm, rescuers were forced to suspend search operations twice.
“There is everything under the rubble - from fire and smoke to toxic chemicals and other hazardous substances,” said Florida Senator Marco Rubio.
To extinguish the fire, a trench about 40 meters long was dug under the rubble of the building. Thus, rescuers tried to expand the search area for survivors.
The UN usually decides to cancel search and rescue operations such as this one 5-7 days after a disaster, if up to that point no survivors have been found during the first days.
However, there are cases when people survived under the rubble much longer: in 1995, a man was rescued from the rubble of a supermarket in South Korea 16 days after the collapse.
As ForumDaily wrote earlier:
- June 24 in Miami-Dade County (Florida) partially a 12-storey building collapsed.
- According to a 2020 study by Shimon Wdowinski, Professor of the Department of Earth and Environment, the building, built in 1981, has plunged into the ground at an alarming rate since the 1990s.
- On the list of the missing listed as a Russian-speaking resident of Brooklynwho moved into the building with his wife.
- In a nearby building in the same complex as a destroyed Florida apartment building, new cracks have appeared in the parking lot, but experts say residents are safe despite a voluntary evacuation.
Read also on ForumDaily:
stdClass Object ([term_id] => 1299 [name] => Florida [taxonomy] => post_tag [slug] => florida)Florida
stdClass Object ([term_id] => 4866 [name] => building [taxonomy] => post_tag [slug] => zdanie)building
stdClass Object ([term_id] => 27234 [name] => Incidents [taxonomy] => category [slug] => kriminal)Incidents
Do you want more important and interesting news about life in the USA and immigration to America? Subscribe to our page in Facebook. Choose the "Display Priority" option and read us first. Also, don't forget to subscribe to our РєР ° РЅР ° Р »РІ Telegram - there are many interesting things. And join thousands of readers ForumDaily Woman и ForumDaily New York - there you will find a lot of interesting and positive information.