Introduction Eurotunnel has other many names which are Channel Tunnel and Channel. The name Eurotunnel came from the company which controls it and who won the tender. This is a 50.450 km rail that connects France with England. Its starts from Strait of Dover and ends in Coquelles in France and passes through Folkestone and Kent. Its the second largest rail tunnel in the world and the longest undersea tunnel with a distance of 37.9 km. Brief history In 1751 this period Napolitic engineers looked for new ways of crossing the sea to the other side which led to the competition which was supposed to show the best initiative and creativity. In 1752 , Albert Mathieu proposed a horse drawn traffic, this was after the signing of the Treaty of Armenians. 1974 saw a tunnel in the UK which was started and after construction of 250 meters it was abandoned due to financial constraints. Also within this period France tried but also they stopped. In 1984 the idea was supported by both Margaret Thatcher and Francois Mitterrand and it was put under consideration. Eurotunnel Group which was later to manage the project was formed in 1986. In 1987 the excavation began and early 1991 a breakthrough was achieved and they begun equipping and finishing the line. Late 1994 saw its completion. There was big celebration witnessed by both head of states; UK and France. Structure of Eurotunnel The structural data of Eurotunnel was considered important for the stability of the excavations and against external factors like the earth quakes. Since these region had various kinds of rocks like the Mesozoic and Paleogene it was considered well documentation was necessary both in terms of seabed topography and its geology. The seabed of Strait was a result of Quaternary erosion after several periods of emergence. The seabed reaches a maximum of 60m along the tunnel alignment. The Strait can be divided into two parts that is the UK part consisting of the undisturbed structure and the French part which is deformed. The construction of the tunnels was mostly done in the Chalk Marl, this was the basal unit of the Chalk. Chalk Marl is a marine deposit that is mainly a mixture of small fossils which because of its high clay content is relatively impervious to water. Chalk is porous hence its risky for the tunnel. More than 85% of the tunnels were constructed within the Chalk Marl. The Chalk is of the Cretaceous age while the Chalk Marl is about 100 million years old. This means that dinosaurs were still wandering on the landmasses when the Chalk Marl was deposited. The re activation of faults that were there in Jurassic and basement rocks caused the fracturing of the Chalk formations in which the tunnels were driven in. The tunnel is situated in the areas that has most highly tectonised zone. This is so because in the French side the route intersects only a few major faults compared to the UK side no major fault with a throw was noticed during tunneling. Between Folkestone and Dover the discontinuities dip steeply with degrees of between 60 and 70. Mott MacDonald who ere the design management employed 500 technical personel. The collective design input was over 1.3 million man hours. Running tunnels and caverns he design of Channel Tunnel comprised of three tun