基于灰度CT图像的岩石孔隙分形维数计算

he characterization of pore structure in rocks is meaningful to discover various mechanics behavior of rocks. Some digital image processing methods integrated with fractal theory were applied to analysize images of rock slices obtained from industry CT, and thus the characteristic of rock pore structure was studied and the relationship between porosity and fractal dimensions was discussed. The gray value of pixels in CT images of rocks are some comprehensive results according to the attenuation coefficient of various materials in correspongding rock elements, and they also reflect the effect of rock pores with all kinds of scale. A partition threshold can be determined by inverse analysis based on the porosity that is measured experimentally, and subsequently binary images of rock pores can be obtained in order to study the topological structures of rock pores. The fractal dimension of rock pore structure is incresing with the increase of rock porosity, and fractal dimensions might be different even though porosities were same. The more complex the structre of rocks is, the larger the fractal diemnsion becomes. It was validated experimentally that fratcal dimension calculated based on gray CT images of rocks is an effective complemental parameter besides porosity and so on, which can well represent the fractal characteristic of rock pores.