Tunnels can be constructed by using a number of different techniques. This

chapter discusses these techniques and highlights the applications and

limitations of the different construction methods. It should not be read in

isolation, but is integrally linked with the support and ground improvement

methods described in Chapter 4. Further, in order to choose the most

appropriate construction technique, aspects such as the ground charac-

teristics, the impact of the tunnel construction on the surroundings, as well

as the economic and health and safety issues need to be considered, i.e. the

construction technique(s) depends on many factors all of which are project

specific. A useful analysis was carried out by Thuro and Plinniger (2003)

to estimate the performance of different tunnel construction techniques

(TBM, roadheader and drill and blast).