| 摘要 |
PROBLEM TO BE SOLVED: To provide a safe and assured method for progressively digging through a rectangular tunnel with shallow top soil covering in soft ground with abundant underground water, without collapsing work face ground and moving the soil covering the tunnel top. SOLUTION: This invention is characterized as follows: two seal materials are vertically placed between the inner surface of a tail tube end behind an excavator provided at the head of a rectangular tunnel and the outer surface of a following tube head, the two being arranged so as to face each other. The starting end of a diaphragm made of a plurality of elongated thin materials or strips that is wound round a winder like a reel, etc. installed behind the excavator is passed between the seal materials and taken out at an external tunnel top surface point behind the following tube and fixed to a stationary frame installed within a backward starting pit. By driving the tunnel forward by means of a main jack installed within the starting pit, the diaphragm is extended to cover the following tube through the external surface of the tunnel top. This diaphragm is effective in shutting off contact between the tunnel body and ground and preventing the movements of tunnel cover soil when the tunnel body slides. COPYRIGHT: (C)2006,JPO&NCIPI
|
