[:en]Sinkhole forms at cultural hub[:]

[:en]A sinkhole 25 meters in diameter caused by a leaking cofferdam wall formed at a West Kowloon Cultural District
construction site, submerging temporary offices.
The WKCD Authority confirmed there was a sinkhole at the construction site of the Lyric Theatre yesterday after
web users posted pictures of tilted temporary offices, construction equipment immersed in water and plastic
barriers sinking into the ground.
“The pipe-pile cofferdam wall sprung a leak at the southeast corner in the early morning, leading to floods up
to two meters in depth in the excavated site,” it said.
“As a result of this breach to the cofferdam, a shallow sinkhole of around 25 meters in diameter emerged
adjacent to the site within the project area.”
It said action was taken by contractor Gammon Construction and the leak stopped at around 9.30am yesterday.
“The authority and Gammon are closely monitoring the situation,” it added.
It said there were no safety issues or injuries resulting from the sinkhole and the works in other areas of the
site were unaffected. The Buildings Department was informed.
An engineer, Albert Lai Kwong-tak, said a large-scale sinkhole is serious and unusual. Lai said a collapse would
have shown prior warnings and that the sinkhole may have caused a loss of sludge due to construction work.
Lai believes the floods happened because the cofferdam wall was not strong enough to withstand the soil
pressure.
The authority could have underestimated the soil pressure around the area, or the complexity of the geological
environment of the land, he said.
“It is possible to stop it if it is just a leak. But from the photos, this is obviously a one-off large-scale
rush of water.”
Lai added that the incident may affect nearby MTR railway structures due to a shift or a loss of soil and being
underwater.
After preliminary investigation of the area near railway premises and facilities, the MTR Corp said it believes
the incident has not affected the structural safety of Kowloon Station. But it would still conduct a full
investigation.
Tony Tse Wai-chuen, legislator for the architectural, surveying, planning and landscape sector, believes that
even though the flooding and sinkhole suddenly occurred, there must have been small leaks or slight settlement
before.
Due to the large excavation area and the presence of other development projects nearby – including the highspeed
railway and Airport Express – the authority should hire land surveyors to monitor the site.
Civic Party lawmaker Tanya Chan Suk-chong said this was not the first time this site had problems, as
construction works had been suspended due to water ingress from the pipe-pile walls last year.
She said the incident shows that construction there is not safe and urged the government to survey the area
again before continuing to build the remaining basement. The theater is scheduled to be completed in 2023.[:]