Tunnel Boring Machines: Trends in Design and Construction of Mechanical Tunnelling

In the past ten years there was a worldwide trend towards increased use of Tunnel Boring Machines (TBM''s). This trend covers a broad variety of applications ranging both from small diameters for sewers and other utilities to large diameters for double track railway and even three-lane highway tunnels. The response to this has been the development of both hard rock machines in the direction for ap...