| 摘要 |
<p>PURPOSE: To improve safety against ejection of mud by forming a separation zone between the upper sectional zone and the lower sectional zone and filling a stable material in the upper zone and filling a bearing liquid after the lower bearing liquid has been replaced by compressed air. CONSTITUTION: A front face 2 of an excavating wall is drilled by advancing a rotary cutter 3. When the central part is choked up, the drilling is stopped by a liquid pressure shield having a central cutter 7. Thereafter, compressed air pressure is applied simultaneously to the bearing liquid to discharge the liquid from the upper sectional zone and draw out a bearing plate in the compressed air pressure, leakage from the gap between the front edge of the cutter arm 6 and the front part 2 of the excavating wall and leakage from side gap is cut off, and further, leakage from the rear edge of the cutter arm 6 to the wall 9 inundated with water is cut off. Then, after the front face 2 of the excavating wall is reinforced by concrete, the upper sectional zone is filled with artificial soil or the like. Subsequently, the bearing liquid in the lower sectional zone is discharged with compressed air pressure. In this way, the lower sectional zone is filled with a bearing liquid.</p> |
