The Application of Soil Nail in The Channel Tunnel
The Channel Tunnel is a railway tunnel from Folkestone, UK to Calais, France, which links England with France. It cost about 8 years to construct this tunnel, from February 12, 1986 to May 7, 1994 and about 10 billion pounds. So it is the biggest project by using private capital in the world.
It consists of three 51-kilometer parallel tunnels, overall length is 153 kilometers, and undersea tunnel is 3×38 kilometers long. It only costs 35 minutes to get through it, so it is the second longest undersea tunnel in the world, only after Seikan Tunnel in Japan. The diameter of two railway tunnel is about 7.6 meters and middle tunnel is a logistics service hole, its diameter is about 4.8 meters.
Geological drilling work was from 1958 to 1987, quantity of important drill hole was about 94. The superficial exploration was undersea 150 meters and deep exploration was undersea 800 meters. Chalk Marl was the main stratum, about 30-meter thick. Owing to high anti-permeability, low hardness, less crack, it is easy to drill.So the tunnel lines were under it.
Compared with land tunnel, undersea tunnel has higher demand of safety and quality. So soil nail has more advantages at the aspect of ensuring undersea tunnel’s quality than rebar. Soil nail can combine drilling, grouting and anchoring at the same time, improve efficiency. Good tenacity, high intensity, it suits for different geological conditions and the body of itself can be cut according to your demands. So, soil nail is more suit for the construction of undersea tunnel.
After the completeness of tunnel, it cost only 3 hours from London to Paris, compared to traditional means of transportation, it shortened about half of the time.
High-quality building materials, advanced technology and safe design ensured its safety and reliability. The channel tunnel became a miracle in architectural history.