| System for Geological Prediction Beyond a Tunnel
Face for TBM Excavation by GPR |
 |
| - Electromagnetic Eye Looking through the Rock - |
| Hiroshi IMAI *1 and Naomitsu YAGISHITA *1 |
Ground Penetrating Radar was installed on the
cutter face of the TBM for hard rocks to excavate the A Tunnel whose diameter
is 12.84 meters. Integration of the geological fore-search system was based
on the radar, to detect any ground conditions impeding the construction schedule,
for example, fracture zones or aquifer. Data acquisition by the system succeeded
from the beginning of TBM excavation, January 2004, and the data were analyzed.
Several reflection planes were determined and the strikes and inclinations
of them were fully consistent with the geological observations. Therefore,
the practical use of the system was confirmed successfully. In the future,
the accumulated EM wave reflection data and their relation to changes in geology
will be investigated through comparison with the TBM mechanical data. |
| keywords: |
electro-magnetic wave, tunnel face,
geologicalfore-search, fracture zone, reflection method |