| 摘要 |
PROBLEM TO BE SOLVED: To provide a shield machine which facilitates linear control in tunnel excavation and which does not damage natural ground at its start, and a starting method therefor. SOLUTION: The shield machine 1 advances into the natural ground 13, while a slope 19 is excavated by cutter heads 10 of upper and lower cutter portions 2 and 3. Earth covering thickness in the advance of the shield machine 1 into the natural ground 13 is set 0.3 times as large in dimension as the height H of the shield machine 1. Thus, since the self-weight of an earthfill section is greater in magnitude than a frictional force which is generated between the natural ground 13 and the shield machine 1 along with the advance of the shield machine 1 into the natural ground 13, the earthfill section is prevented from swelling by being pulled in the penetration direction of the shield machine 1. COPYRIGHT: (C)2010,JPO&INPIT |
