"Progressive collapse" the hypothesis that engineers use to explain the collapse in Miami.

source: www.explica.co

While the authorities are doomed to find some of the 159 missing alive, experts are trying to determine what could have happened in the 8777 Collins Avenue building in Surfside.

A Florida structural engineer is considering several hypotheses about the causes of the "progressive collapse" of the building that collapsed this Thursday in Miami-Dade County, which has left at least four dead and 159 missing as rescue teams continue the desperate search among the rubble.

Authorities remain vigilant in the search for survivors after the partial collapse this morning of the 12-story Champlain Towers South apartment building in the small town of Surfside, bordering Miami Beach. The building overlooking the ocean collapsed in a matter of seconds, and 55 of its 136 units were reduced to rubble, an event for which will have to wait a long time before hearing the official version of the reasons.

Joseph Philippe Colaco, a structural engineer and professor at Florida International University (FIU), made some assumptions about the crash. However, he warned the EFE news agency that it is still premature to venture conclusions in the absence of data on the building, and especially on the work that was done on the roof of the structure.

Progressive collapse

Professor Colaco, who has contributed to the designs of some multi-million dollar projects in the United States, the Middle East, and India, recalled that, according to the mayor of Surfside himself, Charles Burkett, the roof of the building was under construction and inspections later they will determine if the materials or weight of the tools used have been a factor.

From what is known so far, and what a video taken by a security camera shows, the building collapsed from top to bottom, as if they were domino pieces and in what engineers know as a "progressive collapse."

He reminded that the rule used in engineering is that each square foot can contribute a maximum of 40 pounds (18 kg). However, the square feet of the roof are made of reinforced concrete, which can weigh about 100 pounds (45 kg). Suppose contractors placed heavy machinery or cut holes near columns, to give a few examples. In that case, the roof could have collapsed and, at the same time, broke the rule of 40 pounds per square foot of the 12th floor, which ends up producing the so-called "Progressive collapse. "

But Professor Kolako emphasizes that there may be other possible scenarios. For example, the sea salt from this building located on the beachfront has entered possible cracks in its balconies and corroded its structure. Likewise, it cannot be ruled out that the works that were carried out in a neighboring building, and that according to some local officials produced some cracks in the Champlain Towers South that were repaired, may have had to do with the collapse.

He went on to say that rising sea levels were causing parts of the city of Miami to sink and that the foundations of the Surface Building could be affected. However, regarding victims and survivors, the specialist showed little hope: "If they are not picked up in the next few hours, they will perish due to lack of oxygen," he said.

40-year inspection

In 1981, precisely the year that Champlain Towers South was built, the collapse of a five-story building in the coastal town of Cocoa Beach, in central Florida, causing the death of 11 workers, led to the creation of the state Threshold Inspection law that is in effect today. This law added more inspections throughout the construction process of any building that is more than three stories high, or 90 feet (27 meters) high, or exceeds 5,000 square feet (1,525 meters) and can house at least 500 people.

Local authorities have announced that due to an inspection under this law, the roof of the collapsed building in Miami-Dade was under construction. However, the mayor of Surfside has said that this is not considered a factor of the loss in principle.

For now, state and local authorities continue to focus on assisting victims and their families. This Thursday, Ron DeSantis announced that his government would work with property owners in Miami-Dade County to find temporary housing for people. They were displaced as a result of the collapse.

I want to thank my brave first responders who took immediate action to save lives. De Santis, who is visiting the site today, said the state is committed to providing the resources needed to rehabilitate the Florida community. In a statement, his office announced that the governor has also authorized state resources to survey the damage caused to the entire Surfside community and local businesses.