Inside France’s 200 km Grand Paris Express Mega Metro Tunnel Construction Beneath Paris France is building what many engineers consider one of the most ambitious urban transport projects ever attempted in Europe: a 200-km mega metro network beneath the historic ground of Paris. Known as the Grand Paris Express, this underground system is being constructed through one of the world’s most complex urban environments — a dense maze of ancient foundations, existing metro lines, utilities, and protected structures. Using dozens of giant tunnel-boring machines and thousands of precision-engineered concrete segments, engineers are reshaping mobility for more than 12 million residents across the Île-de-France region. The scale, technical difficulty, and strategic vision behind this project have made the Grand Paris Express one of the most remarkable metro construction programs underway anywhere in the world today. Follow Mandarin Tech as we reveal how engineers built a masterpiece deep underground — and shocked the world.
Video Chapters
00:00 Intro
01:00 Project Overview
02:15 Site preparation and early construction works
03:20 How the underground stations are built
04:25 Tunnel Boring Machines
06:11 Production of precast concrete tunnel segments
07:51 How each tunnel ring is assembled
09:08 Managing geological risks and ground settlement
10:38 Saint-Maur–Créteil Station
11:52 Why Paris needs a new transportation network
13:16 Green Paris
14:26 Conclusion





