Currently, the more common way to construct tunnels is a tunnel boring machine (tbm). A tbm is a cylindrical machine with a cross section designed to cut through many types of soil and rock.
How Are Tunnels Made?
Tunnels are an essential part of many infrastructure projects, whether they are used to connect two cities, transport goods, or provide access to an underground network.
But how exactly are tunnels made? This article will provide an overview of how tunnels are constructed and the process involved.
Tunnel construction typically begins with a survey of the proposed tunnel site. This allows engineers to determine the precise route and depth of the tunnel, and to assess the ground conditions.
Once the survey is complete, engineers will create a design for the tunnel. This includes the shape, size, and strength of the tunnel.
Depending on the project, the tunnel may also need to be waterproofed or reinforced with a lining. Once the design is complete, construction of the tunnel can begin.
The most common method of tunnel construction is known as “cut and cover,” where excavation is done from the surface and the tunnel is built from the inside out.
This is the simplest and most cost–effective method for smaller tunnels, such as those used for pipes or electrical cables.
For larger tunnels, such as those used for transportation, engineers may employ a technique known as “drill and blast,” where explosives are used to break up the rock before excavation.