ESTIMATION OF THE CUTTER TORQUE IN PIPE JACKING WITH INNER EXCAVATION SYSTEM

Japanese National Railways developed a new pipe jacking method for constructing an underpass across the railway embankment in 1976. But in earlier stage of its application, the excavation system could not penetrate the gravelly ground and in the worst case, even the cutter arm was broken. This compelled us to estimate the necessary cutter torque from the characteristics of the ground for a rational redesigning of the excavation system.