For prefabricated slab houses with a long service life, the main problem may be the load-bearing wall or the load-bearing column. On the one hand, residents may remove the necessary load-bearing part during use. On the other hand, foundation settlement is also a common phenomenon in rural areas. Uneven settlement will affect the stability of the load-bearing wall and increase the risk of collapse.
After the collapse of the Linfen Hotel in Shanxi, Shanxi carried out special inspections on the safety of housing construction and people gathering places throughout the province.
"We will investigate all houses in the town, including business premises and private houses within one week, mainly based on the year of construction, structure, material, and appearance. There are nearly 10,000 houses." said a person in charge of a town government in Linfen City.
On the morning of August 29, the Juxian Hotel in Chenzhuang Village, Linfen City, Shanxi Province collapsed when it hosted an 80-year-old birthday banquet for an elderly person in nearby Anli Village. A total of 29 people were killed, of which 24 were from Anli Village.
The banquet hall of Juxian Hotel was made up of a yard with prefabricated panels.
The Beijing News reporter learned from a number of construction professionals that the villagers may lack standard design when building their own buildings, and improper behavior during construction and use may also damage the overall structure of the house and increase the risk of house collapse.
After the collapse, the wounded were rushed to the hospital for treatment immediately. According to Xinhua News Agency today, all 28 wounded received effective treatment.
The collapsed building material is prefabricated board, which has been gradually eliminated in recent years
Juxian Hotel is close to the road and is a house built by villagers.
A reporter from the Beijing News learned from Mr. Yao, the village director of Chenzhuang Village, and several villagers that the first floor of the house was built in the 1980s. Due to the continuous increase in road construction in recent years, the original first floor has become On the ground floor, two floors were added, and later a loft, bedroom, and kitchen were built, which have been expanded five or six times in the past decade.
Among them, the banquet hall that collapsed was originally the courtyard between the main house and the back bedroom, used for banquets.
More than ten years ago, the owner of the restaurant built a layer of prefabricated panels above the yard. The rescue team said that the accident was caused by the collapse of the prefabricated panels above the yard.
The main house, kitchen, bedroom and other buildings around the banquet hall are basically intact.
It is understood that prefabricated panels are prefabricated concrete parts that are pre-produced and processed in the factory.
When making the prefabricated board, first nail the hollow model with wooden boards. After placing steel bars on the hollow part of the model, fill the hollow part with cement, and then knock off the board. The rest is the prefabricated board, which can be transported directly to the construction site. Install it.
Chen Gong, a structural engineer from an architectural design institute in Beijing, told the Beijing News that compared with the popular on-site concrete, precast slabs were widely used in my country before the end of the last century because of their low cost and ease of use.
“At that time, steel and concrete were expensive. The houses were mostly brick-concrete structures. Workers built the walls on site and then covered them with precast panels.”
After about 2000, with the decline in the price of steel and concrete, and the maturity of concrete technology, the functional requirements of buildings became more complex, and prefabricated slabs and brick-concrete structures were gradually replaced.
Several villagers in Anli Village and Chenzhuang Village told the Beijing News that there was no manufacturer of prefabricated panels in this village. The prefabricated panels used to build houses in the past were mostly purchased from Nanliang Village, Dengzhuang Town, about 10 kilometers apart, but in recent years it has been rarely use.
On September 1, a person in charge of the Dengzhuang town government told the Beijing News reporter that there were indeed many prefabricated board factories in Dengzhuang town earlier, and the products they produced were sold to the surrounding areas, "but there have been very few in the past ten years. Last year, all (factories) were banned for environmental reasons."
In Nanliang Village, at the door of a villager who had produced prefabricated panels seven or eight years ago, several piles of prefabricated panels were piled up. “There has been no market for a long time.” Another prefabricated panel factory in this village is in a sorghum field. There are piles of prefabricated slabs. According to villagers, the boss has already switched to driving excavators.
A reporter from the Beijing News visited and found that most of the houses in Nanliang Village are made of reinforced concrete. Only the vegetable garden and barn can see prefabricated panels. In Chenzhuang Village, where the Juxian Hotel is located, most of them are reinforced concrete structures, the villagers told Reporter, most of these houses were built after 2000, "basically no prefabricated panels are used."
The precast slab collapses or there is a problem with the load
A villager who lives opposite the Juxian Hotel said that there was originally a wall on the east side of the banquet hall, and the east side of the prefabricated panels was built on this wall. "When the collapse occurred, the wall fell outside."
Chen Gong, a construction engineer, said that when prefabricated slabs are used, they are generally laid on a load-bearing wall or column, and a concrete surface layer is poured on it to meet waterproof requirements and enhance integrity.
"Once the load-bearing wall or connection is damaged, the prefabricated slab is at risk of collapse."
It is understood that the design service life of prefabricated panels is the same as that of ordinary residential houses, which is 50 years.
In Chen Gong’s opinion, for prefabricated slab houses with a long service life, the main problem may be the load-bearing wall or column. On the one hand, the residents may remove the necessary load-bearing part during use, and on the other hand, the foundation settlement It is also a common phenomenon in rural areas. Uneven settlement will affect the stability of load-bearing walls and increase the risk of collapse.
Some villagers said that heavy rain fell continuously for more than ten days before the hotel collapsed, and the east wall of the banquet hall where the collapse occurred was low in terrain, prone to accumulation of water, and may have some damage to the foundation.
Many villagers reported that two uninhabited houses collapsed in the heavy rain in Taosi Village, two kilometers away from the hotel.
In addition, a Xiangfen county firefighter who was drawing at the scene after the accident told the Beijing News reporter that the banquet hall was 13.6 meters long and 12.4 meters wide.
A structural engineer who asked not to be named stated that the use of prefabricated floor slabs in an area of hundreds of square meters requires the use of steel bars to connect the load-bearing columns, prefabricated slabs and surrounding buildings into a whole.
However, “the use of prefabricated slabs for such a large area must be reinforced, but the cross-section of the floor in the picture is very neat, and the steel bars are not visible.”
Not only that, according to villagers near the Juxian Hotel, about five or six years ago, in order to prevent rain, the hotel added a colored steel shed above the prefabricated panels of the banquet hall.
The above-mentioned structural engineer stated that the foundation bearing capacity of the house is limited, and the cover of the color steel shed will bring hidden dangers to the stability of the foundation; if the position of the color steel shed bracket is not selected properly, the original load-bearing structure may be damaged; It may change the use function of the floor, and change the roof panel that was originally used as the roof into the floor of the attic, and create new safety hazards.
In an interview with a reporter from the Beijing News, the village cadres of Chenzhuang Village said that the hotel was constructed without a professional design, but only hired two major workers to work as small workers with their families.
According to CCTV News, on August 30, the Shanxi Provincial People's Government established a major accident investigation team for the collapse of a hotel in Xiangfen County on August 29 to investigate the accident.
Currently, the investigation is still ongoing.
There is a gap in the supervision of self-built houses in rural areas, and local house inspections are carried out
A reporter from the Beijing News learned from many villagers in Chenzhuang and Anli villages that most of the houses were built in the villages around 2000. "Building houses on their own homesteads is not like a city, so there is basically no need for approval."
On September 1, the director of the Taosi Township Police Station told the Beijing News that in general, self-built houses in rural areas are within the prescribed area of the homestead. "It is okay to build a first floor, or to build a villa, no one is in charge."
In Nanliang Village, a reporter from the Beijing News saw a family building a house. The owner told the Beijing News reporter that he had hired a few workers to help with the construction, and he did it himself. "No formalities are required."
"The self-built houses in rural areas currently lack legal standards." An interviewed architect said.
In order to strengthen the supervision and management of construction activities and ensure the quality and safety of construction projects, my country passed the "Construction Law of the People's Republic of China" in 1997. This law stipulates the process and related responsibilities of construction activities, but the construction law also It is clarified that "this law does not apply to the construction activities of farmers self-built low-rise houses."
In January 2014, the Ministry of Housing and Urban-Rural Development issued the "Implementation Opinions on Rural Construction Planning Permits", which stated that "in the township or village planning area, the construction of rural villagers’ houses... According to the requirements of this implementation opinion, apply for a permit for rural construction planning".
However, Chen Gong told the Beijing News reporter that in real life, "local management of self-built houses in rural areas is weak, and each place is different."
With the occurrence of the collapse, not only Taosi Township, but also surrounding towns and villages have entered an "exceptional period."
At noon on September 1, the staff of Dengzhuang Town, a few kilometers away from Taosi Township, were busy in a group, and multiple departments jointly investigated large public places such as village banquet halls.
"We will conduct an inspection of all houses in the town, including business premises and private houses, within a week, mainly depending on the year of construction, structure, material, and appearance. There are nearly 10,000 houses." A person in charge of the Dengzhuang Town Government said.
According to Xinhua News Agency today (September 1), of the 28 wounded, 2 lightly wounded went home after their injuries were treated, and the remaining 26 wounded were treated at Linfen City People’s Hospital and Linfen Central Hospital.
Xue Feng, a member of the expert group and director of the Department of Traumatology and Orthopedics at Peking University People's Hospital, said that the accident was caused by smashing injuries, and many of the wounded had broken bones. Many critically ill patients were basically turned into safety after the efforts of medical staff, without life threatening.
The expert group also provided personalized psychological treatment and comfort to the wounded and their families.
Beijing News reporter Xiang Kai Han Qinke