Abstract: A shield tunneling method of excavating a tunnel with an optional cross section by rotating a center cutter about an axis extending in the direction of propulsion and revolving a planetary cutter around the axis so as to excavate the region between the profile of excavation by the center cutter and the desired profile of excavation. A machine for practicing the method includes a center cutter supported by the body of the machine so as to be rotatable about an axis extending in the direction of propulsion of the body, a rotary body rotatable about the same axis as the center cutter, a planetary cutter supported by the rotary body so as to be movable radially of the rotary body, and operating device for moving the planetary cutter in the radial direction to permit the planetary cutter to revolve along a locus during the rotation of the rotary body so that the planetary cutter excavates the above-mentioned region.

Abstract: A rock crushing device which crushes a rock by an expandable member which is, after being inserted into a borehole formed in the rock, expanded by pressure of a liquid material injected thereinto, including a liquid pressure measuring device provided in a liquid supply hose and a processor connected to the liquid pressure measuring device for processing the liquid pressure converted into electric signals and the time interval during which the liquid pressure is measured, wherein a valve provided in the liquid supply hose is controlled to be closed when the value of the value corresponding to the decreased pressure of liquid material of the liquid pressure measured by the processor exceeds a predetermined value.