Chinese investigators announce cause of mysterious shaking in Shenzhen’s SEG Plaza
- Planned work includes removing antennas and repairing damage – but plaza will no longer be among Shenzhen’s 10 tallest buildings
- Property agent says the landlord may have to offer substantially discounted rent to get tenants back and restore confidence
They said that while the building was safe overall, necessary rectification work – including removing the long antennas and repairing “damage accumulated” over the past two decades – was expected to take over a month, according to a statement on Thursday.
The 350-metre (1,150-feet) landmark skyscraper in the Huaqiangbei electronics district began swaying on the afternoon of May 18, prompting authorities to evacuate thousands of people from the building. It was closed for safety inspections after more tremors were reported in the following days.
After two months of testing, investigators have ruled out potential factors such as the subway running below the plaza, vibration caused by air-conditioning units and nearby construction projects, the statement said.
“The perceived vibration of the SEG Plaza building is caused by a combination of vortex-induced resonance of the rooftop masts and changes to the dynamic characteristics of the building,” it said.
Investigators conducted 63 vibration tests which showed that when the masts vibrated at a frequency of 2.12 Hz, “bending and torsion vibration” of the building occurred, the statement said.
The team of experts said the building had suffered “accumulative damage” over the past two decades, especially on floors connected to the rooftop masts. However, they stressed that such damage did not affect the building’s overall safety.
