Cause of Shenzhen tower shaking found

A shaking skyscraper in Shenzhen, which saw people fleeing in panic two months ago, was rocked by wind patterns, experts said yesterday.

The 300-meter SEG Plaza tower began to wobble on May 18, prompting the evacuation of hundreds of occupants and causing pedestrians in the Futian district to run.

Authorities ruled out an earthquake as the cause of the wobbling and sealed the building to seek the cause.

Engineering experts now say they conclude it was caused by wind-related "vortex-induced vibration" as well as the building's mast.

"The main structure of SEG Plaza tower is safe under ... normal use conditions and can continue to be used," they said.

"We believe that removing the mast can solve the vibrations issue."

Demolition and tower repairs will be carried out "in the near future," the report added.

Vibrations due to wind or earthquakes "can cause fatigue cracks and even collapse" in high-rise buildings, according to an April study in the engineering journal Shock and Vibration.

Experts say that SEG Plaza, built in 2000, shook 21 times between May 18 and 20.