HOW TUNNELS ARE DUG UNDER CITIES

Added: 2026-05-16

[00:00:00]What if I told you engineers can dig huge tunnels beneath busy cities without most people above even noticing?

[00:00:07]Instead of digging from the surface, engineers often use giant machines called tunnel boring machines, or TBMs.

[00:00:15]These massive rotating machines slowly cut through soil and rock underground while supporting the tunnel walls at the same time.

[00:00:22]As the machine moves forward, concrete segments are placed behind it, creating a strong tunnel lining that stops the ground from collapsing.

[00:00:30]Engineers also constantly monitor vibrations, pressure, and nearby buildings to make sure roads, homes, and infrastructure above stay stable and safe.

[00:00:40]In softer ground, pressure systems and waterproof barriers are used to stop tunnels from flooding or sinking.

[00:00:46]So even beneath crowded cities full of traffic, buildings, and utilities, engineers can carve out entire underground transport systems hidden below our feet.

[00:00:57]Because modern tunneling isn't just digging underground, it's precision engineering beneath an entire city.

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