CONCISE FORMULA OF BARTON'S STRAIGHT EDGE METHOD FOR JOINT ROUGHNESS COEFFICIENT

Joint Roughness Coefficient (JRC ) is an equivalent index which describes mechanical effect of rock joint surface angle of ascent. This paper investigates the geometrical characters of Barton's straight edge method and derives a concise formula for JRC from the Barton's straight edge method. t The paper further tests the rationality and availability of JRC modified straight edge with practical example.