STARTING METHOD OF TUNNEL BORING MACHINE AND STARTING MECHANISM OF TUNNEL BORING MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a starting method of tunnel boring machine and a starting mechanism of tunnel boring machine capable of taking a reaction force for excavation in constructing a tunnel by a cast-in-place concrete method without using the NATM construction method.;SOLUTION: A tunnel boring machine 5 is started by transmitting a thrust to a bored tunnel 1 via a reaction truss 3 and a temporarily assembled ring 7 installed behind the tunnel boring machine 5, and a temporarily assembled adjustment ring 9 having a thrust release mechanism is assembled in front of the temporarily assembled ring 7 while an inner form 11 is assembled in front of the temporarily assembled adjustment ring 9. Besides, an end plate 31 is installed at a position of tunnel mouth and an additional rib 25 is fixed to an outer peripheral surface 49 of the temporarily assembled adjustment ring 9. Next, lining concrete is placed between the inner form 11 and a pit wall 29 using the end plate 31 as an end form. Then, the thrust of the tunnel boring machine 5 acting on the temporarily assembled adjustment ring 9 is released by using the thrust release mechanism and the inner form 11 is removed in a state that the thrust is transmitted from the lining concrete to the temporarily assembled ring 7 through the additional rib 25.;COPYRIGHT: (C)2012,JPO&INPIT