#tunnel engineering

Tunnel engineering has become one of the most important disciplines in modern infrastructure development. Whether for highways, railways, or metro systems, tunnels improve connectivity by overcoming geographical challenges while reducing travel distances and environmental impact.

At Introsoft Solutions, our tunnel engineering consultancy focuses on innovative design, structural safety, geological assessment, and efficient project execution. Every tunnel project requires detailed planning, advanced engineering analysis, and continuous quality monitoring.

Modern tunnel construction incorporates advanced technologies to improve durability, safety, ventilation, drainage, and operational performance.

Some interesting facts and statistics about Nora, the new TBM:

The main body, which includes its cutter head, is 21.5 feet in diameter, 42.6 feet long, and weighs 2.2 million pounds.

The trailing gear—which processes tunnel muck and positions pre-case concrete liners—is an additional 426.5 feet long and weighs 520,000 pounds. View a scale model video. 

That means the entire machine stretches nearly 470 feet and weighs more than 2.7 million pounds.

Nora was built to withstand 30 bar of pressure – believed to be the most of any TBM every manufactured. That’s about 11 times the amount of pressure that comes out of a garden hose. The machine was built to withstand that much pressure because workers encountered huge inflows of water under immense head pressure when the aqueduct was first built more than 70 years ago.

To deal with groundwater inflows, Nora also has a dewatering system that can pump out 2,500 gallons per minute.

Nora will be pushing into a very porous formation of limestone. To ensure this rock is sound for drilling, it will first need to be hardened. To do this, the TBM includes three drills that can drill ahead in 30 different positions to inject grout into the porous rock, making it one hard mass.

Assembly of the TBMs on site here in Doha in November ready for launch the following day. The TBMs here are mobilised in full-length mode, whereas in London this is almost never a possibility due to small constrained sites.