1993 Fiscal Year Final Research Report Summary

Experimental study on the practicality of Borehole Hammer

Research Project

Project/Area Number	03555134
Research Category	Grant-in-Aid for Developmental Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	資源開発工学
Research Institution	KYOTO UNIVERSITY
Principal Investigator	KIKUCHI Kohkichi Kyoto University, Faculuty of Engineering, Professor, 工学部, 教授 (90224899)
Co-Investigator(Kenkyū-buntansha)	MITO Yoshitada Kyoto University, Faculuty of Engineering, Instructor, 工学部, 助手 (40229753) KUSUDA Hiromu Kyoto University, Faculuty of Engineering, Instructor, 工学部, 助手 (90169988)
Project Period (FY)	1991 – 1993
Keywords	rock test / simple test / striking test / borehole test / in situ test / response value / hammer / deformability
Research Abstract	A test system using "Rock Test Hammer" is often used to evaluate rock mass properties, simply. The Strike Response Value is measured by using this machine, and the modulus of elasticity is expected. So, in order to apply this principle to the borehole investigation, we develop a new machine "Borehole Hammer". With regard to this machine, the laboratry testing using rock specimen was carried out and we have a successful results. However, in situ testing has never been made. So we made the in-situ testings using "Borehole Hammer" and borehole expansion tests at the several testing yard(igneous rocks, sedimentary rocks and concrete) in order to grasp the applicability of "Borehole Hammer". As the results, the relationship between strike responce value obtained by "Borehole Hammer" and elasticity tends to linear and the accuracy of testing results is clarifed. Futhermore, taking discontinuity density into account, the equation of the estimation for deformability is suggested and more reliable estimation could have been carried out using strike response value. As the result of in situ testing at the deep borehole, the relationship between testing depth and strike response value is clarified and the applicabilty to the check for the deformation-improvement of rock masses by grouting is also percieved. As the results of above examinations, the applicability of "Borehole Hammer" to the in-situ rock masses is clarified.