The characterization of deep rock joints from Borehole Television image

摘要

The characteristic of deep rock joints affects the mechanical behavior of rock mass in under-ground rock engineering,especially underground oil storage caverns.Borehole Television (BHTV) is used to investigate lithology and deep rock joints characteristic,which is dip direction,aperture and roughness,in the largest underground oil storage caverns in China.Based on the geometry relationship between inclined borehole and joints,the dip angle and dip direction has been identified by 3 points' depth and orientation,and the real aperture has been figured out by depth and orientation of 2 points of the joints trace in the BHTV image.A sinusoid ruler was proposed to measure the fluctuating quantity of the joints in images,and projected the oval roughness of borehole wall to straight line.The joints roughness was estimated by Joint Roughness Coefficient (JRC) through the relationship of Fractal Dimension and Barton's 10 standard profiles.