EARTH RETAINING DEVICE USED FOR METHOD OF BORING CIRCUMFERENTIALLY ENLARGED TUNNEL

摘要

PROBLEM TO BE SOLVED: To provide an earth retaining device which has an earth retaining plate compactly stored when not retaining a facing and which is optimum for a method of boring a circumferentially enlarged tunnel.;SOLUTION: In this earth retaining device 17 used for a method of boring a circumferentially enlarged tunnel, a support plate 18 is slidably attached to the front inner peripheral surface of a rectangular cylindrical boring machine body 2 of a circumferential tunnel boring machine 1 so as to be advanced forward of the boring machine body and retreated into the boring machine body. The base end of the earth retaining plate 20 is pivotally supported at the front end of the support plate so that the front end of the earth retaining plate is erected inward of the boring machine body when the support plate is advanced and fallen along the inner peripheral surface of the boring machine body when the support plate is retreated.;COPYRIGHT: (C)2010,JPO&INPIT