Typhoon Mangkhut: despite swaying high-rises, Hong Kong structures are built to handle strong winds, experts say
Windows are a bigger concern, especially if they have been fitted too tightly and have no room to expand
As buildings swayed and windows shattered under the impact of Typhoon Mangkhut on Sunday, the Hong Kong government and experts were quick to assure residents the city’s architecture had been constructed to deal with strong winds.
One of the buildings worst hit by the typhoon – which caused the highest signal No 10 to be up for about 10 hours – was One Harbourfront, an office complex in Hung Hom that had dozens of windows smashed.
How badly were windows broken in One Harbourfront in Hung Hom, Hong Kong? Took these 30 mins ago. Glasses everywhere and I mean literally everywhere. @SCMPNews #Manghkut If wind blows they can hurt ppl easily pic.twitter.com/X01V8dE1ju
— Phila Siu (Bobby) (@phila_siu) September 16, 2018
Vincent Ho Kui-yip, a former president of the Institute of Surveyors, said the design of high-rise buildings took strong winds into consideration.
“Swaying is normal, the problem is whether the degree is too large,” he said.
While acknowledging the safety could only be decided on a case-by-case basis, Ho said the overall structure for most buildings in Hong Kong should be able to cope with winds.
He said windows were a bigger concern.
“If [windows are] fitted too tightly and there is no space for them to expand and contract, they might crack.”
Veteran engineer Greg Wong Chak-yan said that, for the past 20 years, windows in Hong Kong had to meet a standard regulated by the Buildings Department and that even bigger ones had been sent to laboratories for testing.
“There are tens of millions of windows in Hong Kong and there could be many reasons why they break, such as them not having been repaired after many years,” he said.
He stressed the number of breakages was still low.
A Buildings Department spokeswoman said all private buildings were required to be capable of safely sustaining a wind load, stated in the Code of Practice on Wind Effects in Hong Kong 2004.
“Private buildings designed to comply with [the code] should be able to withstand a wind load of magnitude as large as that of Typhoon Mangkhut,” she said.
She added the department did not compile separate figures for shaking buildings during typhoons.
Ho advised those who had a window shatter to leave the room and close the door. If all the windows were smashed in a flat, it was unsafe to stay there.
One resident in a 14th-floor Mid-Levels flat said he could feel his home swaying slightly in the afternoon.
“It felt a bit like being in a boat,” the 58-year-old said. “I felt a little bit dizzy.”