| 摘要 |
PURPOSE:To permit the ground quality to be widely and highly accurately measured with little time and efforts by driving an exciter by using the repeated sine-wave modulated by any one of a soft-start mode, an attenuation mode and a combination mode of these two. CONSTITUTION:On a ground G whose stratum is to be measured, an exciter 1 and vibration detectors 2 and 3 are placed at distances. The exciter 1 is driven by the repeated sine-wave modulated by any one of a soft-start mode (a), an attenuation mode (b) and a combination mode of these two (c) to propagate vibrations through the ground G, and the mutual relation between the outputs detected by the two vibration detectors 2 and 3 is obtained to compute the velocity and wavelength of the propagation wave. This permits the ground quality to be measured over a wide range without the need for changing the positions of or the distance between the two vibration detectors 2 and 3. |
