1. INTRODUCTION
Currently under construction to stretch a record length of 57 km, the Gotthard Base tunnel located in Switzerland spans the north of Europe, spanning through the Swiss Alps to the south of Europe. This railway tunnel has been designed to bypass the inefficient route of windy roads and cutting down travel time. The Gotthard Base tunnel consisting of twin tunnels is connected by cross passages at every 325m.
The twin tunnels have been constructed to pass through the main body of Swiss Alps running along the ground level of the mountain massif .The geological make up of the Swiss Alps are three crystalline bodies separated by sedimentary zones, hence making construction very difficult in some locations.
2. BACKGROUND
In the past two decades the route over Gotthard pass has been one of most important routes through the Alps for cargo and transport. Only in the past decade, statistics show a dramatic increase of amount of freight being transferred: In 1990 an estimated 40m tonnes went by road, in 2001 that had risen to 90m tonnes, with further big increases expected by 2010 Currently the freight train running on the existing narrow rail system are only allowed to carry 2000 tonnes and travelling speeds are extremely slow. The Gotthard Base tunnel was designed to cut down the amount of traffic through the Swiss Alps and extend the 2000 tonnes restriction to a 4000 tonnes load. Freight trains will be able to travel 150km/hr, while passenger trains can hit 250km/hr, cutting down travelling time by almost an hour.
3. FORMATION OF THE SWISS ALPS
The Swiss Alps are a mountain range formed by the convergence and collision of the European and African tectonic plates approximately 100 million years ago. As a result of this collision, the Tethys Ocean basin gets pushed upward by the African tectonic plate and into the Eurasian tectonic plate. The bottom of the Tethys Sea experiences enormous pressures,