Redesigning of the shopping centre led to the deaths of more than 500 people
For the first time Russia has published the causes of the tragic collapse of the shopping center Sampoong, that happened in Seoul in June 1995. 501 people died.Note that Russia is actively constructing shopping malls across the country based on technologies that were already in use in Korea.
Does Russia assess the tragic experience of its neighbours?
When people, having no understanding on the building safety, start changing on their own the building designs, the number of victims of such decisions could be overwhelming.
Professor Lan Chung, the Director of the Centre for Studies of Seismic Activities of the National Research Laboratory of Korea narrated the reasons for the collapse of the shopping centre Sampoong.
So, the shopping centre at an affluent zone of Seoul was only 5.5 years old. It was built very fast. The entire central Seoul used to come here for lunch. The warning “signals" alarmed a day prior to the disaster. A crack appeared on the roof. On the day of the collapse in the very morning itself when the air conditioner was on operation water started dripping down from the fifth floor ceiling. The management of the Centre simply turn off the air conditioner. Alarm signs intensified. A bent was formed in one place on the fifth floor. Vibrations appeared, due to which the store dishes rattled the glasses. Around noon ceilings of the fifth and fourth floors have started cracking. However, only at 14:00 hours a meeting was held in the office of the director of the shopping centre, in which the decision to call an expert was taken. And the staffs were reassured: “Everything is under control, you can work”.
At 15:00 engineer arrived, photographed the changes and after an hour the conclusions were given: “Nothing terrible, cracks can be patched up”. Later it was found that he was not sufficiently trained. At 17:30, on 29 June, within 20 seconds the huge five-story building collapsed within itself, like a house of cards. Almost none could escape.
New technologies do not provide protection "from the stupid"The Inquiry Commission investigating into the causes of the disaster (with Mr Chung as its Executive Secretary) has established the main reason as the deviation from the original design during the construction period at the request of the building owner, who was seeking to maximize the use of internal area. The shopping centre was constructed as per the new system that was in fashion in those days. Flooring was made from flat slabs interconnected by reinforced tie rods and were relied to the columns. There were no ceiling beams. In these circumstances, when there is no additional support, the tension at the point of conjugation of slabs and columns must be calculated very accurately, and during the process of usage, by no means it should not exceed the calculated magnitude or direction. If one of the columns would be "cut", the load impact would immediately get redistributed to the rest, and a chain reaction could happen.
In the design the designers have planned columns with a diameter of 800 mm. Shopping centre owner, as he himself, using his own company, constructed the building, having decided to have more internal space for better storage of goods, reduced the column diameter to 600. In addition to this, although as per the design, the column was to be supported with 16 reinforced bars, running along the column, only eight were fixed.
Floor slabs are also linked together with the reinforcement bars. The designer has arranged them along the depth of 5 cm below the floor surface, in order to provide added strength. But, during the construction they were further lowered by another five cm to get extra space for the laying of all sorts of communication channels. Accordingly, the load impact on the reinforcement has gone up. Besides, the length of these tie rods was inadequate in order to compensate the increased load. That is, they did not go too deep into the slabs. Under the originally planned arrangement the length of the tie rods was sufficient, but with the new it was not sufficient.
Finally, the supporting panels did not represent as an entirely single whole unit. At first, concrete was poured for the filling of slabs and the shock absorbers on the column up to the level of the tying rods, then the tying rods were placed and the concrete was poured over them later. Thus, the pouring in these areas was not homogeneous, and therefore, became less reliable. According to the specialists, the floor safety, because of all of these violations, has decreased by three times!
The load impact on the whole structure, on the contrary, has increased compared with what was in the original design. The fifth floor was originally planned to be a skating rink. But then the owner of the complex, knowing that the restaurants generate much more profit, has redesigned the floor into a restaurant. Thus the floor load has increased by 25%. Besides, additional openings were made on the ceilings for the garbage duct. And on the walls of the fifth floor holes were made for better ventilation.
In such conditions, the catastrophe, as it can be told, was inevitable. The only question left was: when? Just one column, unable to bear the load, a little heeled down, and started a chain reaction. That is what happened on 29 June, 1995. At the same time, the Commission found out that there was certain slope of slabs identified already on the previous day. But, having no understanding on the strength parameters and on the issues of industrial safety, the management of the shopping centre did not pay even the slightest attention on the alarming symptoms.
The results of the building inspections
The Managing Director of Technical Diagnostics of GCE Group, which has to its credit inspections conducted on more than a thousand buildings and hazardous structures, has noted that the problems identified during the diagnostic survey, one way or another, are related to the negligence of the owners and violations of regulatory requirements. "Very often there was no project implementation documentation on the construction works, no maintenance of passport and technical journals on the management of buildings, no timely instrumental survey for determining the building reliability and no routine repair works, and there were no permissions from the supervisory bodies for the alterations of the original design and there was no project documentation at all”.
Statistics on Shopping Centre Collapses from 1 March 2010.*
| Date | City | Incident | Causes | Victims |
| 1 June |
Nizhniy Novgorod | Collapse of ceiling elements in the shopping centre "Fantastika" | Failure to comply with building norms | No injuries |
| 17 April |
Volgograd |
Collapse of the ceiling canopy in Voroshilov shopping center | not known | 2 people hospitalized |
| 7 April |
Sebi (Philippines) | Partial collapse of a shopping centre under construction | not known | 5 workers killed |
| 16 March |
Харьков | Kharkov Collapse of the wall of a commercial office building located at 10, Prospect Pravda | Offset load on the bearing structures while constructing unauthorized superstructure floors | No injuries |
| 24 February |
St. Petersburg | Collapse of the roof of the shopping centre MEGA-Dybenko | Breach of work norms in the roof construction |
No injuries |
| 1 March |
Tbilisi | Collapse of the shopping centre under construction located at Alley Agmashenebeli | Not known | 2 people injured |
* Source: Statistics prepared by the Department of Public Relations
Department of Public Relations,
GCE Group: (812) 325-0621, 331-8353
www.gce.ru
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