A test system using Rock Test Hammer is often used to evaluate rock mass properties, simply.Strike response value is measured by using this equipment, and the modulus of elasticity and uni-axial strength are expected. In order to apply this principle to the borehole logging, a new tool “Borehole Hammer” was developed. Laboratry testing on rock specimen using this tool has already been carried out and we have successful results.
In this study we conducted the in-situ tests using “Borehole Hammer” and borehole expansion tests in order to grasp the applicability of “Borehole Hammer” to the estimation of rock mass deformability. As the results, the relationship between strike response value obtained by “Borehole Hammer” and elasticity tends to linear and the applicability of “Borehole Hammer” to the in-situ rock masses is clarified.