ABSTRACT
Tunnel boring in hard rock has increased continuously since the 1950s, reaching several tens of meters of daily advance rates in competent rock. However, the success of mechanized tunneling is based on a continuous improvement of mechanical excavation during many years of engineering innovations. Pioneering works leading to the construction of modern TBMs include the work done by a Belgian engineer Joseph Maus in 1846 for Mount Cenis Tunnel; the work done by Charles Wilson in 1851 on using disk cutters was patented by Wilson in 1847; a TBM was designed by Beumound for the Chanel Tunnel; TBMs built by Wittaker for the Chanel Tunnel reached daily advance rates of 2.7 m in lower chalk near Folkestone; and a breakthrough by a TBM was designed by James S. Robbins in 1950, reaching daily advance rates of 30 m in limestone in the Humber Sewer Tunnel (Stack 1995; Maidl et al. 2008).
