Underground space stratification scenario
Hanoi is under great pressure from population growth, vehicles and infrastructure needs, while land funds are increasingly limited. Exploiting underground space is therefore becoming an inevitable development direction.
Resolution on planning and adjusting underground space supplements regulations on the 1/500 scale route plan dossier, as a legal basis for establishing, appraising and synchronously implementing underground projects. Accordingly, Hanoi City orients the development of vertical urban structure instead of just expanding horizontally. The ground will be exploited according to scientific depth layers to ensure safety:
Floors from 0 - 15m: Mainly serve people's livelihoods and urban infrastructure such as pedestrian paths, underground parking lots, urban railway support systems, water pipes, electric cables... ; Floors from 15 - 30m: For strategic projects such as urban railways, disaster prevention warehouses, energy reserves... ; Floors from 30 - 50m: For large-scale groundwater reserves and key technical infrastructure pillars serving national defense and security. Under 50m: Unexploited resource reserve area.
Hanoi City's goal is to form a system of interconnected tunnels between the metro, parking lots and commercial centers, helping to directly reduce the load on existing urban areas and open up more development space.
Special mechanisms are needed to attract resources
Experts believe that in many large cities around the world, technical tunnels (common tunnels) are built to synchronously arrange water supply and drainage, electricity, and telecommunications systems. Bringing these works underground not only helps the urban appearance become more spacious but also limits the situation of "mining roads many times" affecting people's lives.
Hanoi City is gradually implementing this direction, but the level of synchronization is still limited. Accordingly, Hanoi City only has a number of underground parking lots in apartment buildings or separate works, not yet interconnected with each other as well as with the common public transport system.
According to Assoc. Prof. Dr. Pham Hoang Kien (University of Transport), Hanoi City currently only uses less than 5% of underground space potential. The biggest barrier today is not technology or geology, but the lack of interconnection.
The three main components include: underground traffic, underground technical infrastructure and underground urban space (trade, services, parking lots) still exist disjointedly. Experts emphasize two key keywords for Hanoi: "deep digging" (diversified functional development) and "connection" (underground network connection with ground infrastructure).
Representatives of the Department of Structure - Urban Transport Infrastructure (Hanoi Department of Construction) said that Hanoi City has issued a List of underground works to encourage investment (Resolution 433). In the coming time, Hanoi City will prioritize the implementation of: 8 urban railway lines, 5 pedestrian tunnels and 78 underground parking lots.
Experts believe that the biggest problem of Hanoi City is the need to plan and operate underground space as a unified whole. If construction continues to be disjointed, lacking intercommunication between ground, elevated and underground traffic, exploitation efficiency will be difficult to achieve as expected.
