A New Method of Stress Measurement Based upon Elastic Deformation of Core Sample with Stress Relief by Drilling

Takatoshi Ito, Tohoku University, Sendai, Japan, Akio Funato, Fukada Geological Institute, Tokyo, Japan, Tetsuya Tamagawa, Japan Petroleum Exploration, Chiba, Japan, Kazuhiko Tezuka, Japan Petroleum Exploration (JAPEX), Chiba, Japan, Yasuo Yabe, SATREPS, Tokyo, Japan, Shuhei Abe, Saint-Mande Cedex, France, Akimasa Ishida, Ritsumeikan University, Kyoto, Japan and Hiroshi Ogasawara, Ritsumeikan Univ, Kusatsu, Japan