local time, a residential building in the town of Surfside, Miami-Dade County, Florida, suddenly collapsed, and the scene was horrible. The collapse of the 12-storey apartment building, which was later added by developers, directly resulted in 24 deaths and 121 missing.
For this collapse accident, I don't know if you have noticed some details. After paying attention to some details, I feel that this may not be the last such accident, and there may be such accidents in the future.
Why do you say that? Please note that the way of collapse in the collapse video is almost the same as the directional blasting of our house demolition, and it is similar to the way of collapse in 9/11. & nbsp; & nbsp;
What does this collapse mean? It shows that the load-bearing capacity of the structure below is gone, and the load-bearing capacity of the structure suddenly can not bear the weight of the building, so it collapsed directly like directional blasting. & nbsp; & nbsp;
a good building, how can this happen?
If you pay attention to the ruins after the collapse, you will find a very serious problem.
On the one hand, the structural walls of buildings look very thin and the steel bars are very thin. It is difficult to see such structures as pillars and beams on the collapsed ruins, and it is even more difficult to see thick steel bars. In a 13-story building, we should be able to see these structures under normal circumstances, which only shows that the quality of the building is very problematic. These beams and columns collapsed in the collapse of the building.
Moreover , a few days ago, it was reported that the large sand used in the cement of this building may contain a large amount of sea sand. Sea sand can not be used in construction, because sea sand is rich in salt, salt is a compound of chlorine and sodium, chloride ion content in concrete exceeds the standard, chloride ion will corrode steel, resulting in volume expansion of steel, resulting in tension cracking of concrete around steel. Houses built with sea sand often have a service life of only 6 to 10 years, so sea sand is often used for sports sand, home landscaping, and construction sand is usually river sand.
Then, if the building uses sea sand, then this is easy to understand. Because the building is undergoing maintenance, and from the photos disclosed by the media, the pillars of the underground parking lot are indeed cracked seriously, and the shape of the cracked part of the cement is obviously different from what we often see, showing a broken state. If the
steel bar is not thick enough and the quality of cement is not good, then the strength of the structure of the house can be imagined!
On the other hand, the early construction standards in the United States were too low. According to the old standard, the foundation of this kind of building only needs to be hit to the bottom with a certain resistance, rather than hitting the foundation on the bedrock. This means that the foundation of the 1981 building is probably not solid, and after 40 years, the unstable foundation may have buried hidden dangers.
Also, it should be noted that according to local regulations, buildings over 40 years old need to be monitored and recertified for safety. This house is exactly 40 years old, so engineering inspections have been carried out in the past few months, and it has been proved that this is a problematic building and needs major repairs. However, the cost of overhauling the building is up to $15 million, which the residents of the building cannot afford. As a result, the building collapsed before it could be repaired.
It can be seen that the housing inspection system and housing maintenance system in the United States are deficient. In the face of such a dangerous house, there is no money to repair it? A dangerous house can still be allowed to live like this, how can there be no major accidents?
So, since we can find so many problems through this building, it is obviously not an individual problem, but a common problem. If it is a common problem, then who will pay for these problems? If no one pays the bill, how can such accidents be avoided?
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