Development of Rock Stress Measurement Probe Based on The Pilot Hole Wall Deformation Method Laboratory Tests

摘要

The theory and a prototype tool were developed for pilot hole wall deformation measurement. This is a 3- dimensional stress measurement method based on the stress relief principle. A pilot hole is drilled from the bottom of a borehole and the stress measurement probe is inserted into the pilot hole. The differences between the displacements by the elastic stress analysis and those measured by using the probe were within 3% in the uniaxial compression test of an acrylic resin plate with a hole. The stress components which were applied to a cubic Kimachi sandstone specimen with an inclined borehole were evaluated by using the probe within an error of 6% relative to the applied maximum principal stress in a biaxial loading test.