Restraint device of the tube to be used for this method and centering positioning method in the ring - constant curvature curve volume

摘要

PURPOSE: To determine the position of an excavation locus which a casing pipe should pass by binding the casing pipe at three spatial points or more on a curve to be passed, while allowing movement of the pipe along a curve of a constant curvature. ;CONSTITUTION: An inner pipe 5 is inserted into a casing outer pipe 4 of a predetermined curvature and a drilling device 6 is mounted at an end portion of the inner pipe 5. Next, the drilling device 6 is projected from the end portion of the outer pipe 4 and a chuck device 32 holds the outer pipe 4 and the drilling device 6 is driven. Then a propulsion unit 33 propels the chuck device 32 so that the outer pipe 4 is propelled into the ground G with its predetermined curve kept unchanged. In this case, the outer pipe 4 is bound and held at three positions or more in a space above the curve using a curvature-holding binding device 7 securely mounted on a frame 2, while allowing movement of the outer pipe 4 along a curve. The outer pipe 4 is thus bound and held using a simple structure so that the exactness of constant-curvature curve boring can be achieved.;COPYRIGHT: (C)1994,JPO&Japio