| 摘要 |
<p>A method for excavating safely and quickly a tunnel having a large section in which the bedlock near the tunnel is improved and reinforced over the full length of the tunnel construction zone and artificial bedlock arches are built. A top heading (2) is excavated through the full length of the construction zone of the tunnel (1), and curve boring is effected from the top heading (2) at predetermined interval along the periphery of the section of the tunnel (1). A steel pipe (3) is laid in each bored hole and a grouting material is injected into the bedlock near the tunnel from the steel pipe (3) to build artificial bedlock arches (4). Thereafter, the tunnel (1) is excavated, concrete is placed by advancing a suspension form (6) and secondary lining is done.</p> |
