The average person is unaware of how many intricate components are required to build a tunnel, regardless of its location. Although the exact components may vary based on your project, standard tunnels require the following components:
Soil
Segment lining with support measures
Tunnel boring machine (TBM) with hydraulic jacks
Grouting
If you plan on working on an urban tunnel (in a city or large town), you’ll also need to keep the current infrastructure in mind.