Shenzhen Skyscraper Shaking Spurs Safety Alert by U.S. Consulate

The U.S. consulate in southern China’s Guangdong province issued a safety alert warning Americans to avoid a 75-story skyscraper in Shenzhen after the building mysteriously wobbled during a fine day Tuesday.

U.S. citizens should avoid SEG Plaza and the nearby Huaqiangbei area, the consulate said Wednesday in a statement. The alert will remain in force until further notice, it said.

Thousands of people in the SEG Plaza and surrounding areas fled after the building wobbled Tuesday. The tower’s owner, Shenzhen Electronics Group Co., said tenants felt it shake at 12:31 p.m., and building management immediately organized an evacuation. No signs of cracking on the ground or damaged curtain walls were detected, it said in a statement on its website.

An initial investigation by the Guangdong provincial government’s safety watchdog said the building was shaking vertically rather than swaying side to side. Experts said various factors might cause the shaking, including wind, railway operation and temperature, a government document circulated online showed. A person close to the Guangdong government said the document represents findings from the initial investigation, and the final conclusion is pending further studies.

The main structure of the building remains stable, and no inclination has been detected, according to the document. An inspection is underway to determine when the building can be put back into use, it said.

The document didn’t explain how the factors could have caused the building’s movement. Lu Jianxin, a senior engineer at Zhongke Construction Group, said in a television interview that it is possible that wind caused momentary resonance of the building.

According to Shenzhen’s weather authority, local wind speed was at a maximum of 9 meters per second when the shaking occurred. A temperature difference of nearly 8 degrees Celsius was recorded that day.

Two railway lines go through the underground near the SEG Plaza. The building has 75 floors above ground and four below, and it hosts Asia’s largest electronics market. The 356-meter building was put into use in 2000.

Shenzhen has been enamored with tall buildings as it boomed from a region of rice paddies and green fields four decades ago into a metropolis of more than 12 million people. The city has 297 buildings at least 150 meters tall, the second-most in the world after Hong Kong, according to the website skyscrapercenter.com. In 2015, urban planners and aviation authorities quarreled over how close high rises could be built to the international airport.

Shares of Shenzhen SEG Co., whose controlling shareholder is Shenzhen Electronics Group, lost 6.5% over the past two days and fell to the lowest level in three months. The stock is now down 16% this year.

In 1999, the SEG Plaza building wobbled the day after its antenna was installed, according to Jin Dianqi, who studied the project for his master's degree thesis in 2001. Jin, who is the chief operating officer of Shenzhen Urban Public Safety and Technology Institute, is a member of the expert team studying the latest incident.

According to Jin’s 2001 article, the 1999 shaking happened during a day with fine weather and mild wind. It was caused by miscalculation in the antenna design that caused resonance. The construction team cut off part of the antenna to fix the issue, according to Jin.

Bloomberg contributed to this story.

Contact editor Han Wei (weihan@caixin.com) and editor Bob Simison (bobsimison@caixin.com)

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