The city beneath the city

In spite of its small size, the city has a population of five million, and it is an important communications node by both sea and air. Given that 693 square kilometres has to find room for as many people as the whole of the population of Norway, we can understand that the city must be crowded and that it has reached the limits of expansion.

This is why the authorities are now considering moving some of Singapore’s infrastructure underground. Several ministries have drawn up a list of proposals for how underground caverns could be used for this purpose.

The possibilities include moving underground everything from water treatment plants and reservoirs to airport logistics and PC component microchip manufacture. Every area must be carefully evaluated before any decision is taken, and this is what the Singaporean authorities want Norwegian tunnel experts to do.

High reputation abroad

The fact is that Norwegian expertise in building and using underground facilities is in high repute in other countries – not least where exploiting the construction characteristics of the rock mass is concerned. Since the Second World War, Norwegian tunnel engineers have gained solid experience in building tunnels and caverns for many different purposes, including storage halls for oil and gas, hydropower projects and swimming pools and sports areas.

Today, SINTEF Building Research is in the process of developing subsea tunnel projects in Iceland, the Åland Islands and the Faeroes. Our scientists are acting as consultants in the construction of a 25 km-long sewage tunnel under Hong Kong, and are also involved in other projects in China and India. Almost four years ago, SINTEF won its first contract for preliminary rock mechanics studies in Singapore, for a gigantic underground oil storage facility.

Now we have received a request to support the development of a master plan for Singapore, and to help to evaluate and assess a range of solutions for each of its ten areas.

Basis for decision-making

“We put a lot of work into winning projects in other countries”, says SINTEF research manager Eivind Grøv. “Besides being intellectually rewarding and exciting, they are a useful complement to our Norwegian projects”.

SINTEF is operating in a consortium together with Multiconsult and a local company, TriTech. “We set up this joint effort some years ago, and it has turned out to be a useful bridgehead into Singapore”, says Grøv.

The Trondheim scientists, who were awarded the contract a couple of months ago, have been using the time since then to collect examples of similar projects that have already been performed such fields. In the course of the next nine months, and on the basis of three examples from each field, they are to develop appropriate solutions for Singapore. The ministries involved will use these as a basis for decision-making.

Large dimensions

“We are talking about large areas all over the island,” says chief scientist Ming Lu of SINTEF Building Research, who has led the earlier Norwegian efforts in SIngapore. “If these facilities are built, the process will involve digging shafts, boring access tunnels and building huge caverns. It is extremely interesting for us to contribute to a job like this, since we are talking here about the first project of such dimensions anywhere in the world”.

As far as we know, only in Helsinki is there already such planned use of underground area. There, it is not simply a matter of solving the problem of lack of space, but also of moving unaesthetic or noisy elements of the infrastructure away from the surface, thus making valuable areas of land available to the city’s residents.

“Today, we don’t know what they will decide to build in the future, but no matter what they turn out to be, it is easy to imagine that these could involve enormous storage rooms. Singapore and Hong Kong have the two largest harbours in the world, where huge numbers of containers are loaded and discharged at an incredible speed. Even if the authorities decide to relocate only the port warehouses underground, that alone would mean clearing quite a few cubic kilometres of rock,” says Eivind Grøv.