Singapore digs deep for ideas to build downwards

Studies being done to see if more facilities can be built underground

By Feng Zengkun, The Straits Times, 4 Nov 2013

UNDERGROUND classrooms, libraries, swimming pools and even a science city for up to 4,200 workers - these are some of the proposals which have been unearthed even as studies into Singapore building downwards gather pace.

So far, the country has already engaged in several major underground projects, including a common tunnel under Marina Bay for telecommunications cables, power lines, water and refuse pipes, and the Jurong Rock Caverns for storing petroleum products.

But a host of studies are trying to see if more can be put below ground.

The Ministry of National Development is looking to see if facilities such as reservoirs, power plants and landfills can be clustered underground to save surface land.

Singapore's Central Business District, new Marina Bay Downtown and its future southern waterfront district may also be linked by an extensive underground road network beyond 2030. The Land Transport Authority is considering a plan that involves a series of subterranean ring roads.

The Building and Construction Authority's (BCA) geological office has also been studying underground rock types and conditions of sites in western and north-eastern Singapore.

The survey, which should be completed by next year, will be used to develop geological models that show the thickness, distribution and structure of the bedrock, as well as major faults in the earth.

"This will help us to identify and evaluate various land uses for potential underground developments," said a BCA spokesman.

The National University of Singapore (NUS), Nanyang Technological University and industrial landlord JTC Corporation have all recently finished exploratory studies on the possible underground developments.

Engineers told The Straits Times that Singapore's subterranean level could be divided into several tiers in the future.

The top layer, stretching about 20m from the surface, could include utilities such as water and gas pipes.

Train stations and tunnels, offices, malls, carparks, laboratories and other facilities intended for people could occupy the second layer between 15m and 40m deep.

Facilities which involve fewer people, such as cable tunnels, oil storage caverns and reservoirs, could occupy the deepest layer from 30m to 130m.

Several issues still need to be resolved.

"We need to find ways to make underground spaces comfortable for people, such as through the use of natural light and vertical greenery," said Professor Yong Kwet Yew, NUS vice-president of campus infrastructure.

The university's exploratory study had identified sports facilities, libraries, auditoriums and research laboratories as some uses that could go under its Kent Ridge campus. But Prof Yong said more detailed studies need to be done.

Going underground: Examples of existing infrastructure

By Feng Zengkun, The Straits Times, 4 Nov 2013

COMMON SERVICES TUNNEL (5M - 10M DEEP)

- A 20km network of tunnels in Marina Bay housing water pipes, electrical and data cables, cooling pipes and a refuse conveying system.

- This minimises traffic disruption during maintenance works.

DEEP TUNNEL SEWERAGE SYSTEM (20M - 60M)

- The DTSS uses gravity to move used water to centralised water reclamation plants at the coastal areas.

- Phase one of the system was completed in 2008 and covered Singapore's northern and eastern parts. Phase two, slated to be finished by 2022, will cover western Singapore.

JURONG ROCK CAVERNS (130M)

- The first underground oil storage facility in South-east Asia is located beneath the Banyan Basin off Jurong Island, and stores crude oil and other petroleum products.

SAF UNDERGROUND AMMUNITION FACILITY (DEPTH UNKNOWN)

- This facility at Mandai frees 300ha of land above ground.

- It is cheaper to maintain and causes less environmental damage.

Hong Kong: Moving under to avoid dead end

By Li Xueying, The Straits Times, 4 Nov 2013

GONE underground: train tunnels, a garbage compact centre, a sewage treatment plant and an explosives depot.

Heading down under: a data centre, a government archive and even sports halls.

Burrow deeper into the minds of planning experts and one comes up with visions of an underwater city under Victoria Harbour - a pedestrian corridor with shops and entertainment facilities that connect Hong Kong Island and Kowloon.

There is also a proposal for a subterranean road network under jam-packed Mongkok in Kowloon, so as to free up more ground-level space for shoppers and tourists.

As Mr Samuel Ng, chief geotechnical engineer at the government's Civil Engineering and Development Department, states categorically: "We have to move the city underground; otherwise it's a dead end for Hong Kong."

The mission to go underground has gained even more urgency as the city searches for land to build decent housing for its people, but faces obstacles to developing rural areas from various quarters.

Hong Kong, which has 1,108 sq km of land, has already dug some 400km of underground tunnels for its subway system and water channels. In addition, five rock caverns are being used by the government for the following: a reservoir, a sewage treatment plant, an explosives depot, an MTR station and a garbage compact plant.

There is room underground for more to be done, experts said.

For now, Hong Kong has plans to relocate some 400 government facilities, including civic centres, sports halls and wholesale markets, to rock caverns, which are mainly located in outlying areas. In all, these will yield at least 4 sq km of extra space, said Mr Ng.

There are more ambitious proposals ahead, including for the city centre.

Chief Executive Leung Chun Ying, in his first policy address in January, said his administration "will further explore the potential of developing underground spaces in the urban areas".

A two-year study will be launched at the end of this year. Forty urban areas will be initially selected, before being narrowed down to 15 locations, said Mr Ng.

Mongkok tops his list.

"You cannot even use the term 'wandering on the streets' in Mongkok as it is jam- packed," he said.

Architecture academic Cheung Kwok Pun of Hong Kong University has submitted to the government a proposal for a five-storey basement building under reclaimed land around Victoria Harbour. Totalling 120,000 sq m, it would incorporate offices, a traffic network, carparks and an energy-generating centre. A recreational pedestrian strip could be built beneath the harbour itself.

Such a plan, said Professor Cheung, would help mitigate soaring commercial property prices in premium waterfront areas. At the same time, there will be "synergy" in linking up the financial district of Central with the one coming up in Kowloon East.

However, challenges remain.

A major one is cost. Prof Cheung reckons that it costs twice as much to build underground.

There are also engineering considerations, such as how to keep an underground city well-ventilated and safe from fires.

"If there is a blaze during a football match, what design can ensure that we can safely evacuate hundreds of people above ground?" asked Mr Ng.

Yet another challenge is the tricky issue of land ownership.

Under existing laws, those who own the rights to develop a land parcel also own the rights for what is underground.

"This means that the government has to deal with some private players and figure out how to offer incentives to get their cooperation," said Mr Ng.

He suggested that in future, the government should separate the rights for the two. In Japan, for instance, land that lies 10m or 40m - depending on the situation - under a building foundation belongs to the government.

Japan: It all started with Tokyo's first subway line

By Hau Boon Lai, The Straits Times, 4 Nov 2013

FROM the world's largest floodwater diversion facility to bridge tunnels and massive oil storage tanks across the country, Japan has done them all, using its underground expertise gained from building its extensive subway networks.

Since the first subway line in Tokyo - and in Asia as well - began operations in 1927, Japan's labyrinthine underground network has dug deep. There are now more than 40 subway lines covering the country's major urban centres and accounting for more than five billion rides a year.

Major train stations also anchor some of the country's famous chikagai, or underground shopping streets, providing both the infrastructure and the shopper numbers.

The iconic Tokyo Station, which has an underground space of more than 70,000 sq m and sees more than 400,000 passengers daily, has one of Japan's largest chikagai, boasting more than 100 shops selling souvenirs, ramen, character goods and clothes, as well as restaurants and cafes.

But such space-saving underground malls are not located only in densely populated Tokyo. Prefectures such as Hokkaido and Okayama also have chikagai which are better described as underground shopping malls.

As Mr Yoshio Sumikawa, head of the association for the promotion of shops in the Shibuya chikagai, put it, it is more about the convenience rather than a need to build underground. "Regardless of what weather it is, people can shop here in comfort," he said.

Some underground projects, however, are crisis-driven.

As Japan is typhoon-prone, to protect Tokyo and other cities from floods, the government has built massive anti-flood underground facilities, including the Metropolitan Area Outer Underground Discharge Channel, which channels water from Tokyo's rivers through a tunnel 6.5km long and 50m deep to the Edogawa River in neighbouring Saitama prefecture.

The 1973 oil crisis led to the building of installations across Japan containing oil storage tanks with a capacity of 50 million kilolitres of crude oil.

Also found underground are bicycle parks, telecommunication cables, and even a library.

While some construction companies have shared their visions of futuristic cities that would allow millions to live, work and play 150m below ground, these are still at the conceptual stage.

The bread-and-butter of Japan's underground expansion is still linked to its subway system.

Sendai's new Tozai line is expected to start operations in 2015, and Shinjuku and Shibuya stations are undergoing revamps that would increase their already extensive underground space.

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