Over the years, we have been making good progress in tapping underground spaces, from utility lines to rail lines and roads, to meet the many and growing needs of our urban environment. There are also extensive underground pedestrian links in areas like Marina Bay, which enhance connectivity and allow people to walk in comfort.
As evident in many urban cities, the use of underground space has largely been developed on a first-come-first-served basis. Over time, this hinders further expansion and optimal use of underground space.
By planning and safeguarding the space upfront and with the help of technology, we can unlock the potential of underground space and make better use of it.
Going underground expands our space resources by optimising land use and freeing up valuable surface land for more liveable uses. There are no plans to place housing underground. The priority is to place uses such as rail lines, utilities, warehousing and storage facilities underground.
By placing more essential infrastructure underground, we can dedicate our land for more people-centric uses like housing, parks and community spaces, improving the quality and vibrancy of everyday life in Singapore.
Underground pedestrian links seamlessly connected to MRT lines that run underground enhance connectivity and accessibility for commuters, allowing them to travel in air-conditioned comfort regardless of external weather conditions.
Besides these, using dedicated underground tunnels or ducts for our utilities and infrastructure can increase resilience for these networks by providing a safe, secured and controlled environment for the installation, operation, maintenance and replacement of the networks.
To explore future possibilities to plan, build and make use of underground space, we commissioned a benchmark study of 10 cities to explore the best practices internationally.
The key findings showed Singapore’s progress in underground space usage in comparison with the other major cities, and provided suggestions for how else underground space can be utilised.
Based on 2014 data, Singapore was at the forefront for underground rail development, with rail density1 slightly ahead of London and behind Tokyo. However, Singapore had the lowest density1 for underground pedestrian links among the leading cities developing underground pedestrian networks (UPNs), and was behind Hong Kong and Tokyo for underground road density1.
As Singapore currently only uses deep underground cavern space for storage, the study suggested that Singapore could consider learning from other cities which had made use of cavern space for other uses such as utility plants, and data centres.
1: Density is defined as route length per unit of metropolitan area.
To reap the full benefits of underground space use, the underground space has to be planned upfront, together with planning the above ground, to ensure compatibility and integration of underground uses with above ground uses.
Underground spaces should also be safeguard early for future uses. To do that, we are leveraging on technology and smart data in our planning efforts:
Shallow underground space in many cities has an extensive and complex network of utility lines, especially under roads. Proper management and organisation of these lines will ensure that services to homes and businesses are not disrupted and that the laying and maintenance of these lines can be carried out safely with minimal disruptions to the environment.
We have identified areas of improvement for the management of shallow utility lines, which will help make the process more efficient and reduce the frequency of road openings.
Common Services Ducts and Tunnels: An alternative way of laying utility lines
In some instances, utility lines can be better organised by housing them within a Common Services Tunnel, such as the one in Marina Bay, or a Common Services Duct, for smaller-sized distribution lines. These are concrete structures that give easier access to install new lines and maintain existing ones, reducing risk of damaging utility lines and the need for road openings.
Underground space planning is a careful and detailed process, and requires information and coordination from many parties. Having comprehensive, accurate data is vital in the successful development of underground space and to eliminate much of the uncertainty and risk.
There is a lot of potential to push the boundaries in the way we plan and realise underground developments, as we open up a new frontier of space creation.
We are actively working with different parties to come up with new solutions and capabilities as we build up our underground database and adopt new technologies. With this, we can make further advances in underground space planning and usage to achieve a better urban environment for all.