HOLE DEVIATION -A PROBLEM NOT TO BE IGNORE IN OVERCORING CRUSTAL STRESS MEASUREMENT

In this paper, analytical result of strain and displacement in small hole inner wall are made out, and the error between deviation and no deviation is discussed, it shows the error obviously increases with declination of small hole strain and displacement. In this paper, When d=30mm, strain deviation is 30%, and hole diameter deviation is 28%. Maintenance angle transformation is used to change two-deviation circles boundary into regular boundary in calculation, and the measured data in crustal stress piezomagnetic measurement are corrected.