PIPE JACKING APPARATUS

PROBLEM TO BE SOLVED: To provide a pipe jacking apparatus which can shorten time for a pipe jacking operation, and which can be simplified and miniaturized. SOLUTION: In this pipe jacking apparatus 24 for use in a pipe jacking method, a plurality of cylinder devices 51a, 51b, 52a and 52b divided into two groups are provided on a movable carriage 29 for pushing a pipe in the state of supporting it; a back end of each of the cylinder devices has a locking portion 56; and a rail device 26 is provided with a plurality of portions 37a, 37b, 38a and 38b to be locked. The expansion and contraction of the piston rods 55 of the cylinder devices 51a and 51b of a first group and those of the piston rods 55 of the cylinder devices 52a and 52b of a second group are alternately repeated. Thus, the movable carrier advances to push the pipe, while the locking portion of the expanding piston rod is engaged with the portion to be locked and while the locking portion of the contracting piston rod is disengaged from the locking portion and goes over the front adjoining locking portion forward from the back. COPYRIGHT: (C)2009,JPO&INPIT