Uses the arch tunnelling machine the base rock tunnel excavation construction method

摘要

PURPOSE: To provide a bedrock tunnel excavation method capable of excavating and forming a tunnel with a large section safely and efficiently. ;CONSTITUTION: While excavating advancement headings 1 on both sides downward of an arch tunnel section with an excavating machine 12, the circumference of tunnel section is slid and excavated in a ring-cut-shape with an arch excavating machine 20 equipped with an excavator 24 in a movable manner along an arch on an arch holder 21. Arch concrete as the outside layer of an obtained arch circumferential space section 2 is placed to form a shell. According to the constitution, while ensuring the safety, the residual arch circumference space section 2a is used for a free surface, and a bedrock in the arch concrete 3 is efficiently excavated by an explosion.;COPYRIGHT: (C)1996,JPO