open access

https://hdl.handle.net/2115/44221

Influence of Stress Larger than Preload but Acted for Shorter Duration in Tangent Modulus Method : A New Method to Measure In-situ Rock Stress

英語

2010-10

International Society for Rock Mechanics

Influence of stress concentration at rock sampling on the in-situ rock stress value estimated by tangent modulus method, which is one of the oriented core methods for in-situ rock stress measurement, was experimentally investigated. Cylindrical specimens of Kimachi sandstone were preloaded at 30% UCS for 24 hour simulating in-situ stress and then a triangular shape-loading up to 40% UCS simulating stress concentration which took approx. 1 min. were carried out. Loading up to 50% UCS was applied to the specimen twice after certain delay time. Bending points were observed at 40% UCS for 0 to 1 hour delay time, at 30% UCS and 40% UCS for the 3 hour delay time, and at 30% UCS for 1 and 3 day delay time. The bending point was not observed for 1 week delay time. It is considered that the memory of concentrated stress acted at rock sampling for a short time can be lost and in-situ rock stress which acted for geological long-term can be accurately estimated if the test is carried out after an appropriate delay time.

会議発表論文

Accepted Manuscript

Indian National Group of ISRM