| 摘要 |
<p>PURPOSE:To enable predicting ground density and status with high accuracy and wideness by detecting gamma ray from a gamma ray source in a body penetrated into the ground and simultaneously measuring the parameters of penetration resistance. CONSTITUTION:A penetration hole 1 and an examination hole 4 are bored in a ground A with a certain distance and a penetration body 3 which contains a gamma ray source 2 at the front tip, is penetrated in the penetration hole 1 and a probe 5 is hung down with a cable 9 in the examination hole 4. Following the penetration of the penetration body 3, the probe 5 is moved to keep a gammaray detector 6 at the same depth as the gamma ray source 2. By supplying power from a high voltage source 7 to the detector 6 to detect gamma ray, amplifying the detected signal with a preamplifier 8, and counting it with a counter 10, the density of the ground is measured. Also by measuring the penetration resistance at a certain depth with a penetration resistance sensor, the ground status is predicted based on those data.</p> |
