Researchers discuss methods that the National Institute of Standards and Technology (NIST) can use to find out the cause of the disaster. Soon after the Champlain Towers collapsed in Surfside, Florida, the search for answers began. In a rare move, the National Institute of Standards and Technology (NIST) said the leadership promise would be a lengthy process to investigate the event that killed 64 people. The involvement of the National Institute of Standards and Technology (NIST) - which also led to the investigations into 9/11 - could signal a change in US manufacturing laws. p>
The crop fall was not an earthquake or other natural disaster. While many ideas have been quoted to explain this incident, it can take a long time to come up with solid answers. It is not easy to understand the fact that the vast majority of structural debris at this point is just rubble. However, researchers have ways of determining the factors that led to this colossal tragedy - even if the clues are broken into smithereens.
The National Institute of Standards and Technology (NIST) declined to comment at this point, so Ares contacted researchers in the field to understand how to conduct this type of research.
Some have suggested that a defect in the construction or masterplan caused the 40-year-old structure to collapse. Others have stated that salt water can erode part of the hull. Still others have suggested that construction in a nearby building, or the differential location of the basement, could be a factor. "It makes sense to start with a wide range of possibilities — there are other things, but it's hard to guess now," said Ben Schaefer, a professor of civil and systems engineering at Johns Hopkins University. He said there could also be more than one reason. "It's more than just a possibility — probably," he told Ares.
Where do we start?
To start, the team will try to understand what the 136-unit apartment building would look like before it collapses, both through documents and through the building. According to Julio Ramirez, a professor in Purdue University's School of Civil Engineering — who has done much research on the earthquake that toppled the building — the National Institute of Standards and Technology (NIST) will likely look at the original structural drawings and drawings.
The previous document states that the structure - which consists mostly of reinforced concrete with steel reinforcement - is intended for masonry, and the latter shows how it was constructed. These documents, along with the building code at the time the tower was built, can help determine the pre-disaster condition of the building, and show which parts of the structure might have been tighter.
"Before you even think about [evaluating] all of these scenarios, you should first say, 'Well, what do we really think was the starting point? “The National Institute of Standards and Technology (NIST) can also measure the raw amount of concrete and rebar—whether in the form of rubble or a stationary device still fairly intact—at a point in the amount of material used,” Schaefer said. Applications.For example, some have raised concerns that there appears to be less steel reinforcement than in various parts of the structure in the 1970s. Ramirez also noted that at this point, the researchers could look at whether there is corrosion such as the product of a saltwater intrusion. to the concrete and erosion of the rebar inside - and that appears to be the case.At the site, the team could also check to see if "differential leveling" had taken place, meaning different parts of the foundation were sinking at different rates, and see if Differential settlement has been an issue. It depends on whether it is being checked, on purpose or as part of site clearance, unless NIST destroys the building's foundation, which shows it is worth further investigation. Schaefer said Allen is not a very likely scenario," said Schaefer. It will be a surprise."
More search for Evidence
It's also possible - and the team already appears - to have collected examples and perspectives on the site. According to Schaefer, they are collecting concrete and steel for further testing to determine to the best of their ability the condition of the building on the day of the collapse. Ramirez told Arras that the team may have removed larger parts of the building for further inspection. The BBC had previously reported that "[raw materials] are being taken to a large warehouse for examination". Schaefer said it's also possible that NIST will talk to people who witnessed the accident and through any videos it might be combing through. to find. He noted that the film can be useful when trying to come up with plausible scenarios. He can't say for sure that NIST is using computer simulations to test their collapse theories, but if that happens, the movie might help.
Based on its findings, NIST may also attempt to obtain information on the construction of an adjacent apartment building near the accident. There is also a lot of history of potential combing operations, such as identifying the activities that take place under the building during its life, as well as examining how the masonry fatigue near the structure. "The cover is definitely harder," Schaefer noted.
In general, it is difficult to say how far NIST will go in research. "If the initial evaluation said there was an obvious build flaw, for example, and it took 40 years to come to fruition, the organization might not dig much deeper," Schaefer said.
NIST has a large and well-equipped laboratory that can assist it in examining samples taken from the site. Ramirez said the team likely collected the rubble and the few remaining buildings. "This allows them to assess whether there is a significant difference in the properties of the material between the two parts," he told Arras.
NIST will likely test existing debris using both destructive and non-destructive methods. The team may use these methods on collected material or agent material of the same type. Non-destructive methods include the use of radar or echo-echo tests. When debris is used in larger areas - for example, a piece of concrete still inside - it indicates how much rebar is inside the sample and how much is there.
For destructive testing, the team can finally use a uniaxial machine -- also known as an all-encompassing test machine -- to apply pressure to a material in a variety of ways. To test them for tensile and compressive strength, one characteristic of this process is to break the core - so they can determine how long it will take. According to Ramirez, the team will likely remove a core (usually 3" by 6") from a piece of concrete (make sure there is no rebar in the core). Concrete is not particularly homogeneous: not all pieces of gravel, rocks and sand are scattered in it. Likewise, the nucleus may have a larger mass, Ramirez said. This can affect test results. Likewise, the strength of samples taken from the site may be compromised due to the amount of force present in the building collapse. "Typically, researchers take multiple cores and run multiple tests to make sure the differences are average," he said.
Depending on the rest of her work, NIST may choose computer simulations using its data and observations. According to Ramirez, the team may eventually use structural analysis software — similar to the ones it uses when designing something. Instead, the team can implement its findings and recreate the crash using more advanced tools, such as finite element analysis. This element is mostly used in aviation and can include complex geometry, irregular materials, etc.
Programs like ABAQUS can do this, and it appears that NIST has used IT, at least in the past. Based on previous findings and videos of the tower's collapse, the team can use this simulation to test their ideas. "Obviously it's going to take some time. Even with the power of computers and other things, you can imagine how difficult that must be."
According to Schaeffer, every 50 major events that have occurred in the past 50 years have, to one degree or another, led to changes in building codes in the United States. He said he would be shocked if no change was made — perhaps in how erosion is prevented or building inspections organized. But it is too early to guess.
"This discipline is very committed to learning from failure. These failures are rare, which means that we are generally successful, but the goal is certainly not to have anything at this level of disaster." p>
Searching for evidence among the ruins of the Champlain Tower
It is sometimes difficult to write objectively about the progress of SpaceX. The i...
Last Thursday, the Russian space station's new large unit, Navka, was finally conn...
We are now - often horrifyingly - watching what happens to the virus and ...