The large-scale collapse may be due to the degree of wear and tear of the building and improper gas supply
A gas explosion occurred in a five-story building in Nizhny Tagil, causing two of the six entrances to collapse. Judging by the data coming from various sources, there are many oddities in this incident… Expert Stanislav Mityushin spoke about the possible causes of the tragedy.
The explosion occurred in a residential building on Sibirskaya Street. According to preliminary data, the cause of the tragedy was a domestic gas explosion. The emergency services also report that they are considering the version of a malfunction of the gas equipment or a violation of its operation. There is no official data yet on where in the entrance the explosion was localized. But some Telegram channels write that it could have occurred in the basement of the building. Also, a number of media outlets mention the explosion of a certain gas cylinder.
Another oddity is the statements of the residents of the building. 15 minutes before the explosion, the residents saw unknown men in gas workers' uniforms. According to them, two of them went from apartment to apartment in the neighboring building to check the gas equipment, but they were thrown out, after which one of the men hit the gas pipe. Another local resident said that he saw gas workers two days ago. However, as the acting prosecutor of the Sverdlovsk region stated, there is no confirmation of the data that gas service employees went to this building. The last official inspection of the gas equipment system in the residential building took place on June 26, and it was in good working order then.
So what could have caused such a destructive gas explosion? MK reported about this
«Let's not consider versions with gas cylinders, because in the event of a gas cylinder explosion, any consequences are possible, especially if it explodes under supporting structures. These versions should be considered by the investigation. So far, as far as I know, the main version is an explosion of household gas.
When we talk about gas explosions, we as specialists always say a very simple phrase: «We physically cannot completely exclude a gas explosion in an apartment, given that there are about 40 million or even slightly more subscribers in our country.» Against the background of such cases, it is worth saying that any tragedies are a combination of several factors that directly affect the fact that we have an explosion. A gas leak itself is a factor that depends on an annual inspection, and a factor that depends on the owner. A leak can occur, among other things, due to the fault of the owners, including during operation. As you understand, we cannot assign an inspector to each apartment on a permanent basis who would be nearby when using a gas stove. This is physically impossible. From the point of view of using gas in everyday life, our population has lost the sense of danger. After all, gas is a substance that, if gas appliances are used incorrectly, can lead to such tragedies.
As for possible technical reasons… Let's assume that there was a gas leak. The second factor that was superimposed is, most likely, insufficient gas odorization. Our gas itself does not smell. This «gas smell» is provided by a special fragrance, which is added at the preparation stages, when it is transferred from the main networks to the village and city ones. With such gas contamination, long before the moment when we have a risk of explosion, the smell of the fragrance becomes so strong that even neighbors, passing by the door of the apartment, long before the moment of danger will smell this smell. Most likely, one of the factors for checking the consequence should be the degree of gas odorization: to what extent the addition of fragrance to the gas is carried out in accordance with the standards.
The third factor is a violation of air exchange. Very few residents understand that the degree of risk is affected by elementary things that are not even directly related to gas. This is, for example, the installation and connection of kitchen hoods with fans, the serviceability of existing ventilation ducts. This is necessary so that the gas does not accumulate in one room, but leaves. Even replacing wooden windows with sealed plastic ones significantly increases the risk of air exchange violation, since there is no inflow of fresh air into the kitchen, and the exhaust ducts stop working. These factors are what, probably, every resident who uses gas in an apartment should understand.
Against the background of what was happening in red line, when information about the tragedy began to appear, information appeared that, according to the gas inspection, the wear of the house structures is no more than 30%. Against the background of such a collapse — this is the first thing that should be questioned. Because a house in good technical condition, with the necessary reserve of bearing capacity, should not be subject to such collapses. This is a very serious factor that affects the severity of the consequences.
— Yes, of course. We have been talking for a long time about the need to put things in order, including with the inspection of gasified houses. Those series of houses that are subject to this kind of collapse should be very seriously checked for stability in the event of a gas explosion in the apartment. We cannot completely exclude an explosion, but we must reduce the risks and severity of the consequences. And, unfortunately, at the moment, no one in the country is systematically engaged in this.
— I will give you one example from the old Soviet past. Initially, when mass gasification of apartment buildings began, gas was brought into these houses underground through basements. At the very beginning of gasification, there were already cases of explosions in these apartment buildings. At that time, Rostekhnadzor and technical authorities decided to urgently remove gas networks from the basements of houses. All over the country, in many regions, these houses were modernized, gas networks were removed en masse from basements to the facades of buildings. In this situation, I can't say that the gas was brought in through the basement, but if so, then this is a serious violation of current regulations. Current regulations prohibit this. I really hope that this is not the case, although I really don't see gas pipelines on the facade from the video footage. So this is one of the questions.