The shaking skyscraper-SEG: Can you understand the 2nd monitoring data? What's the wobbling future?

on may 25 the shenzhen government released the follow-up monitoring report about the seg tower on may 18 the seg tower in shenzhen experienced severe shaking and 15 000 people were evacuated on may 19 the building experienced shaking again on the evening of may 19 the shenzhen municipal government released the first inspection data through its official weibo the chinese version of twitter claiming that several professional organizations were monitoring the vibration tilt and subsidence of the scg tower in real time and that all three indicators were far less than the normative allowable values it showed no abnormalities yet at about 12 30 p.m on may 20 the shaking occurred again a reporter from wuhan morning post a chinese media entered the building at 12 55 pm that day and felt dizziness and nausea due to the shaking an office lady told the reporter that this shaking was even longer than the last time previously a woman who works at seg tower posted on the internet on the evening of may 13 saying that she felt the building shake that day in other words between may 13 and may 20 the building had shaken four times on may 22 the party secretary of the chinese communist party in guangdong province also the highest ranking provincial official led the provincial governor to shenzhen to inspect the building this official has stated we insist on life first safety first do a good job in handling the situation properly so what has the government done since then on may 25 the official wechat account of the shenzhen municipal government shenzhen release said that as of noon on the 25th professional organizations continued to monitor the settlement tilt rate acceleration and other conditions of the seg building in real time the expert group stated that as of noon that day the monitoring data was normal and did not exceed the corresponding standard requirements here are the details the inspection report states that the professional organization has completed the modeling and rechecked the calculation of the overall structural system of the building using the latest technology and concluded that the overall structural performance of the building meets the requirements compared to the first inspection data released on may 19 the two sets of data are similar both show no abnormalities in the first set of data it also showed that the maximum acceleration of vibration on the 69th floor of the seg tower occurred at 1 51 pm on the 19th less than the limitation for office and hotel buildings as per chinese regulation the second inspection report produced by the shenzhen municipal government stated the overall performance of the building structure meets the requirements it sounds like a safety statement to the public some netizens interpreted it as government assurance in the chinese media some experts are quoted to say that the building suffered a coincidental resonance phenomenon it is similar to the conclusion of the official report of the preliminary investigation released by the emergency management department of guangdong province on the 19th in that report three factors contributed to the vibration of the building one was the wind the second was the temperature difference which was eight degrees celsius it is said to have a significant impact on the steel structure the third is that two subways pass underneath the building however on may 18 there was no strong wind around the building a maximum wind force of five was recorded on that day people from relevant industries in china have commented anonymously that the current settlement tilt and vibration monitoring results of the seg tower can only indicate the current working conditions of the building they are hardly helpful in identifying the cause of the vibration it will likely take quite a long time to find out the reason for the shaking a structural engineer from the china electronic engineering design institute limited said that once the building has shaken once it's like opening pandora's box it will become more prone to shaking again before the shaking the building's structural components decoration components bolts steel and concrete are tightly connected which all play a role in stopping the vibration once the vibration starts those factors that prevent the vibration are either broken or weakened and one type of vibration could transform to other kinds of vibration finally the whole structure would be dancing if no measures are taken to stop the vibration the subsequent development will go out of control [Music] another netizen posted that it has been difficult to lease the office space from the 40th floor and above so they have been leased to electronic companies for warehousing the load capacity for offices is generally based on 250 kilograms per square meter and the warehouse is generally about 500 kilograms the conversion of office buildings to warehouses has led to the building being heavy at the top and might have induced vibrations suffering from the trade war with the us and the movement of hong kong which is adjacent to shenzhen the vacancy rate of grade a office buildings in shenzhen has reached as high as 25.54 at the end of march 2021. in 2014 the figure was 4.4 percent the seg building plaza has been temporarily closed since may 21. the latest figures show the mainland china is home to 40 of the world's tallest buildings with 2 395 buildings over 150 meters 823 buildings over 200 meters and 95 buildings over 300 meters in all three categories china has the highest number of buildings in the world scg tower is currently the world's tallest steel pipe and concrete structure building in a landmark building in shenzhen the total height is 355.8 meters with 79 floors 75 floors above ground and four floors underground seg tower has created the famous shenzhen speed i.e 2.7 days to build a single floor this performance has been written into the textbooks of junior high schools in mainland china but according to traditional notions in china scg tower hasn't been lucky since day one in may 1999 when the main building was being topped out someone shouted scg plaza is going to fall down it led to chaos in the street where the seg tower was cars were stuck in the street vehicles were abandoned people climbed out of the car windows and stores were left open when people hurried their way out it was later discovered that the relative movement of the clouds drifting and the building caused an optical illusion among the pedestrians the building's designer chen shimin designed a special plaza to facilitate the flow of people given the busy location of scg tower seg was located on a busy street of electronics products and crowds of people however before the construction started the developer of seg group suddenly revised the design and closed up the space turning it into a marketplace for lease chen strongly objected and wrote a letter to the shenzhen municipal government stating that the space could not be closed up and he would not be responsible for any problems if the design was altered but the municipal government filed away the letter and there was no further response on september 30 1999 the building completed construction of the antenna section of the roof and the crew celebrated the 50th anniversary of the chinese communist regime which was coming up the next day october 1. pedestrians on the street noticed that the antenna on the roof was vibrating violently it turned out that the design of the antenna was miscalculated the builder and the designer immediately summoned all the workers cut off the top 26 meters of the antennae and recalculated and installed 13 meter antennae instead a 20 year old master's thesis pointed out that scg tower had problems such as constructing before designing starting construction before the design drawings were finished and modifying the design while constructing last year a lot of anomalies occurred in china such as the shifting of the three gorgeous dam [Music] and the shaking of the human bridge in guangdong the rolling and fluctuating of zhou river bridge in wuhan and so on all of which the officials have not offered satisfactory answers for would people trust the government's announcement this time a chinese netizen commented is the building safe god has already warned us four times