It was confirmed that the upper floor of the apartment building collapsed during construction in Gwangju City shook up to 41 mm.



Although this is a common phenomenon in high-rise buildings, structural authorities are measuring the degree of shaking in real time taking into account the characteristics of the collapsed building.



According to the city of Gwangju today (19th), the authorities are measuring mutations at 30-minute intervals at 29 points including the outer wall of Hwajeong I-Park, the site of the accident.



On the 13th, 21st, 27th, 33rd, and 38th floors, we are checking the movement in the east, west, north, south, and east directions on each side of the building.



As a result of the measurement, it was confirmed that the 38th floor had moved 41 mm to the south around 9 am yesterday.



However, on the same day, around 5 pm, it passed its original location and moved 9 mm north again.



The phenomenon of slight shaking or tilting due to the influence of the wind is common in high-rise buildings.




However, in buildings where the 23rd to 38th floors have partially collapsed, even a slight variation can have serious consequences, so authorities are alert.



In the detailed guidelines for safety and maintenance of facilities by the Ministry of Land, Infrastructure and Transport, the slope of the building is divided into 5 grades (A to E).



A grade is 1/750, B grade is 1/500, C grade is 1/250, D grade is 1/150, and E grade is more than 1/150.



Grade D or lower is considered a serious defect.



If the collapsed apartment is 38 stories high and 117m in height, it is within the range that can be classified as Class A up to 156mm.



However, in the case of a normal building, it is only a calculation, and it has no meaning in setting the allowable range for an apartment where an unprecedented collapse accident has occurred.



An official from Gwangju City said, "There cannot be a separate standard, so we decided to discuss additional measures once the mutation value exceeds 45 mm after discussion with experts."