| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic prospecting method for specifying pile length with high detection precision without being affected by terrestrial magnetism even in the case of the pile having a small number of reinforcing bars, such as a cast-in-place pile, or when a prospecting hole must be arranged separated from the pile by footing. SOLUTION: A magnetic field generator 4 made of a coil, or the like and a three-dimensional magnetic sensor 8 are inserted into a nonmagnetic guide pipe 3 and are moved in the direction of a prospecting axis, and power is supplied from a power supply 5 to the magnetic field generator 4 for generating a magnetic field and magnetizing a foundation pillar 1 for measuring the strength of the magnetic field. The distance between the magnetic field generator 4 and the three-dimensional magnetic sensor 8 is set to at least two times larger than the distance between the foundation pillar 1 and the three-dimensional magnetic sensor 8 for moving in the direction of the prospecting axis while maintaining the set distance. COPYRIGHT: (C)2006,JPO&NCIPI |
