Huge deep station completes Hong Kong West Island Line

The ‘monumental’ Sai Ying Pun station, with lift shafts nearly 90 m deep, finally opened in Hong Kong last year. It completed the long-awaited £1.3bn West Island Line, which extends MTR’s metro on Hong Kong’s crowded mountain island by 3km.

The station was built deep below Hong Kong to avoid disruption above ground.
The station was built deep below Hong Kong to avoid disruption above ground.

Rather than the shallow cut-and-cover design planned 30 years ago, the 228m long station – one of three on the new route – was tunnelled out of solid rock 50m down. It is linked to four large entrances by 1,100m of passages that snake under a forest of skyscraper piles.

New depths

Writing in the latest issue of the ICE Civil Engineering journal, Hong-Wing Tam of joint-venture designer Arup says, 'The original alignment along the main seafront road would have created a significant disturbance to the public. The new alignment therefore moves inland towards the hillside, with the station in a deep cavern below the foundations of existing buildings.'

Steep sloping ground means the four passenger lifts at the 'mid-levels' entrance have a drop of 86.7m, making them among the deepest metro elevators in the world. All the shafts and passages had to be carved out of either solid rock or temporarily frozen soft ground - hard either way.

'Engineering effort'

'A lot of engineering effort' was required, concludes Tam. 'With hilly terrain, an urban site surrounded by buildings, many functions fitting together into tight spaces and the determination to minimise disturbance to the community, the project had to satisfy a lot of challenges.

But it's all been worth it. 'With the opening of Sai Ying Pun station, though-train access to all communities along the norther corridor of Hong Hong Island has been made available,' he says. 'Different areas, from the seafront to the mid-levels, are well served with the four monumental underground entrances connecting to the new station. The living quality of the western district, in particular Sai Ying Pun, has been greatly enhanced.'

For further information, please contact ICE Proceedings editor Simon Fullalove at editor@ice.org.uk.

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