Original title: The collapse of an apartment in the United States caused 5 deaths and hundreds of people were missing. Is there a sign of building collapse?
China News Service, June 27, reported that as of the 26th local time, the search and rescue operation of the Miami Beach apartment accident in Florida has entered the third day. The accident has caused 5 deaths and hundreds of people are still missing. Local officials said that as the fire under the rubble is still burning, rescuers continue to face difficulties.
At the same time, investigators are trying to clarify the cause of the accident. Satellite data showed that the building site showed signs of subsidence from 1993 to 1999. There are also engineering reports showing that the concrete structural slab under the floor of the building’s swimming pool has “major structural damage” and must be fully repaired.
The picture shows a mess of damaged tall buildings.
The fire deep in the ruins of the collapsed apartment is difficult to extinguish, hindering search and rescue
The “sister building” also has unknown risks?
According to reports, on the 26th, rescuers continued to search and rescue at the collapse site. Local officials said the death toll from the accident rose to 5, and the number of unaccounted for dropped slightly to 156.
However, the fire under the rubble is still burning. Miami-Dade County Sheriff Kava said at a press conference, “It’s very difficult to find the source of the fire. So they are working day and night. These fire rescue crews are under the rubble trying to solve this problem so that they can move on, but The fire hindered our search work.”
On the same day, Florida Governor DeSantis said that out of cautious consideration, local officials are considering evacuating the residents of the “sister building” of the collapsed apartment because the structures of the two buildings are very similar. Since the south tower of the apartment collapsed on the 24th, the residents of the north tower have remained in the building.
DeSantis said at the press conference, “(Sisters) it was built by the same designer during the same period, so they are considering cooperating. I know they are considering evacuation, but in the end this is what the mayor needs to make. decision.”
The picture shows the excavator cleaning up the site.
Is there a sign of building collapse?
Satellite data shows signs of subsidence at the site of the building
At the same time, the cause of the accident is still under investigation. Two factors are of concern. One is the construction of this building before the security check, and the other is that the building built on the filled wetland has been used since the 1990s. Continue to sink.
According to Miami Dade County security inspection regulations, the building must be re-certified every 40 years. The south building of the apartment completed in 1981 is in compliance with the regulations, and the roofing works will be implemented in 2021. County officials emphasized that there is no indication that there is a causal relationship between the project and the collapse of the south side.
On the other hand, US media quoted structural engineer Greg Batista as saying that concrete repair and spalling problems may cause collapse. When part of the surface of the concrete falls off or cracks, the problem of spalling may occur.
Research led by Florida International University (FIU) environmental science professor Shimon Wdowinski has also received attention. Satellite data showed that the building site showed signs of subsidence from 1993 to 1999.
Dovinsky said: “I don’t know if I can predict a collapse, but we did find that this building moved in the 1990s.” He explained: “It’s very subtle, but it was discovered by satellites.” He described The sinking “processes slowly” rather than sinking quickly.
In addition, the Associated Press reported that the 2018 engineering report of the engineering company Morabito Consultants for the building showed that the concrete structural slab under the floor of the swimming pool of the building had “major structural damage” and must be fully repaired. , And large cracks and peeling of the garage concrete beams and walls.
According to the report, although the report did not warn of the imminent danger of damage to the building, and it is not clear whether the damage they observed was related to the collapse of the building, the report pointed out that the building does need to spend a lot of money to fully repair systemic problems.
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