| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently sample data reflecting dynamic physical properties of the ground by small number of workers and simple work to infer hardness and softness of the ground and the distribution of a cavity and a loosened part in an extremely shallow underground part. SOLUTION: An impedance mapping method for the ground is provided with a base plate 14 placed on a ground surface, a reaction mass 18 vibrating vertically using a piston 16 integrated with the base plate as an axis, and acceleration meters 20, 22 loaded on the base plate and the reaction mass. A vibrator- type hypocenter 10 according to a system in which a reaction force of the reaction mass is transmitted to the ground surface through the base plate is used to obtain an impedance value of the ground at a measurement point from vibration frequency and vibration acceleration, when the vibrator type hypocenter is vibrated, and the operation is done at a plurality of different measurement points to display the impedance distribution of the ground.</p> |
