基于孔内影像的岩石节理粗糙度特征研究

目前对岩石结构表面粗糙度的研究往往只局限于地表,难以反映深部岩石节理粗糙度的特征。钻孔孔壁上节理轮廓线包含有三维信息的特点,本文开展了基于数字钻孔摄像技术的岩石节理粗糙度分形特征的研究,利用数字钻孔摄像系统获取地下深度岩石节理全景图,采用边缘检测技术从全景图中提取出节理轮廓线,对其进行空间变换和视距离变换得到地下岩石节理粗糙表面轮廓线的真实状况。与Barton提出的10条标准剖面曲线进行对比得到每条轮廓线的JRC值,并计算其分形维数,根据最小二乘法原理拟合出JRC与分形维数之间的关系为:(D)=JRC=-541.9x2+1362x-818.53。本文研究内容为描述地下深部天然节理的结构及其特征提供了基础,对更深入地研究地下深部岩石节理的表面空间状况有重要的意义。

STUDY FOR ROUGHNESS OF ROCK JOINTS IN FRACTAL RESEARCH BASED ON PANORAMIC BOREHOLE IMAGES

At present, the study of rock structural surface roughness is often confined to the earth's surface. So, it is difficult to reflect the characteristics of the deep rock joints roughness. The drill wall joint profile contains the characteristics of 3D information. This paper has carried out the research of fractal characteristics of rock joints roughness based on the digital borehole camera technology, obtained panorama of underground drilling rock joints using digital camera system, extracted rock joint contour line using edge detection technology, then got the real rough surface contour by space transformation and distance transformation. This paper has got the JRC value of rock joint contour line by compared with the 10 contour line profile curve which Barton had put forward and calculate their fractal dimensions. According to the principle of least squares method, we can fit the relationship between the fractal dimension and JRC and that is (D)=JRC=-541.9x2+1362x-818.53. This paper has provided the basis for describing the structure and characteristics of the deep-seated natural joint. The results is important significance because it is meaningful for the more in-depth study about the surface of the rock joint which is located in deep underground.