| 摘要 |
<p>PURPOSE:To discriminate characteristics such as a layer structure and a property of the ground by installing an oscillation sensor, which receives the perpendicular component or the like of oscillation, at three or more points on the ground to be examined and simultaneously measuring a slight shock at respective points and analyzing measured perpendicular oscillation data or the like. CONSTITUTION:A perpendicular component detection signal and a horizontal component detection signal of the oscillation detected by oscillations sensors 1 and 2a to 2c at points A and B1 to B3 are amplified by a signal amplifier 3 and are subjected to A/D conversion and are taken into a data analyzing and discriminating means 5 together with oscillation data for analysis. Next, the filter processing and spectrum analysis including FFT (operation based on fast Fourier transformation) are performed to obtain the coherence, a correlation coefficient, and a phase difference between waves obtained by observing an object frequency by equally distant oscillation sensors. When data of the horizontal component exists, the coming direction of the principal wave is obtained, and data of the horizontal component obtained by sensors 1 and 2a to 2c is decomposed in the coming direction of the wave and the direction orthogonal to it, and motions of the ground surface in a plane parallel with the coming direction of the principal wave and a plane orthogonal to this coming direction are obtained as the rotation locus of ground surface corpuscular motion, and it is discriminated whether the excellent oscillation wave is a surface wave or not, and a variance curve is calculated.</p> |
