PURPOSE: To perform safe and reliable excavation and lining by a method wherein an enlarging section is excessively excavated by the overcutter of a closed type rotary cutter shield machine and, after mud is grouted in the part, a segment is extruded.
CONSTITUTION: In the middle of excavation of a tunnel by a closed type rotary cutter shield machine, a peripheral ground 14 of an enlargement scheduled section is excessively excavated in a shape matching with an enlargement shape by an overcutter mounted on a rotary cutter. Mud having plastic fluidity is grouted in an overbreak-excavated part from the shield machine and excavation is advanced as filling is carried out. Building of segments 12, 12, and 13 containing an ordinary part and an enlarging part is performed. Consecutively, after or during completion of excavation advance of an enlargement scheduled section, an existing segment 13 of the enlargement scheduled section is securely extruded in the overbreak excavated part, filled with mud, together with a short cylinder adapter 21 for enlargement.
TAKANO FUMIYA
HAYASHI FUMIYA
| JPS56100996A | 1981-08-13 |