| 摘要 |
PURPOSE:To make it possible to recognize a form of the breakdown of a bedrock accurately by calculating a variation ratio map based on a measured value obtained by an electrode combination of a measuring electrode row and a reference electrode row provided on the outside surface of a shield machine to make an image display. CONSTITUTION:A measuring dipole electrode row 16 and a reference wenner electrode row 14 are provided on the outside surface of a shield machine 10, and a measuring ratio resistance map is obtained by an electrode combination of both electrodes 14 and 16. A ratio resistance of a bedrock side, a ratio resistance of muddy water side and a layer boundary thickness are calculated by the reference electrode row 14 to obtain a reference ratio resistance map corresponding to the measuring ratio resistance map. After that, the ratio of a measured value of the measuring ratio resistance map to a calculated value of the reference ratio resistance map is calculated to obtain a variation ratio map. An equivalent curve connecting an equal variation ratio from the value of rectangular coordinates of a variation ratio map is obtained to make a display through an image display means 54. |
