Listening practice 6: Tunnels
Watch the documentary Construction of World' s Longest and Deepest Tunnel |
Documentary Film: https://www.youtube.com/watch?v=87WPtO1-
fJc&ab_channel=LifeSecret
Then name the following aspects:
BRIEFLY DESCRIBE THE PROJECT. (LESS THAN A PARAGRAPH)
The Gotthard Base Tunnel, It is the deepest railway tunnel in the world, with a maximum depth of
2,450 m (8,040 ft.) The main purpose of the Gotthard Base Tunnel is to increase local transport
capacity through the Alpine barrier, especially for freight, notably on the Rotterdam–Basel–Genoa
corridor, and more specifically to shift freight volumes from trucks to freight trains.
NAME THE TECHNIQUES USED FOR EXCAVATION.
he running tunnels are excavated by two giant tunnel boring machines (TBMS), while the
multifunctional stations are excavated by traditional drill and blast methods. The excavated
material is converted into concrete aggregates on site to produce sprayed and insitu concrete for
the inner lining of the tunnel system.
NAME THE PROBLEMS THE PROJECT HAD DURING ITS EXECUTION.
the construction difficulties and lessons learnt from the two 30 km long southern TBM drives from
Bodio to Faido under overburden reaching a maximum of 2,400 meters. The project overcame a
major fault zone, squeezing ground conditions and rock bursts. The TBM was blocked by a
collapse, and had to cross water-carrying faults with rock and water temperatures reaching 48°C.
The project also needed to cross weak and potentially risky zones like the Piora Basin. A section of
the tunnel was enlarged after squeezing rock nearly blocked the TBM drive. Expected water
pressure exceeding 160 bars required suitable pre-investigation equipment.
INDICATE HOW THESE PROBLEMS WERE SOLVED.
A waterproofing system with sheet membrane was installed along the whole tunnel length and
extensive testing was carried out.