| 摘要 |
PROBLEM TO BE SOLVED: To accurately monitor thrust applied to each part of an pipe jacking pipe, at a low cost in a thrust monitor used for a underground tunnel pipeline pipe jacking method. SOLUTION: A plurality of stress measuring devices 20 and a pressure measuring device 30 for measuring jack pressure filled in a pressing side circuit of an intermediate pressing jack 6 are provided in the specified positions of a pipe jacking pipe row. The stress measuring device 20 comprises triple layers of a measuring layer 21 and stress buffer layers and detects observed stress at each point of the measuring layer 21 by a plurality of strain gauges 23 fitted to the measuring layer 21. A control computer 10 computes working thrust in each measured cross section on the basis of measured stress and pressure and prepares various control drawings on the basis of these working thrust data. The control computer 10 also computes computed stress at each point of the stress measured cross section on the basis of a stress plane (regression plane) determined from observed stress data. |
