Abstract: Various attribute information of fissures such as length,width and density can be extracted from CT scanning images of oriented rock samples that are systematically collected through field work.These information can play a important role in defining spatial distribution of fissure networks within rocks.Both trace distribution and fissure network distribution follow the power-law distribution,thus statistical analysis can be performed on the field-collected trace data.The extension length and interlink of fissures on 2D images can be inversed to 3D space by applying stereological techniques,so as to deduce 3D fissure length and density distribution and realize conversion of rock fissure attributes from 2D to 3D.This approach was applied in Gaosong ore field.Based on analysis of the traces on the CT scanning images,we obtained the maximum trace length of 64.1 mm,the minimum of 2.2 mm,a mean of 16.69 mm and a variance of 12.33 mm.The fissures were divided into 9 groups,and the probability distribution of diameters of each group was obtained.Simulation was performed on the extracted trace data when the fractal dimension(α)is 1.5 and 2.5 respectively.The mean of fissure diameter was 27.60 mm,and fracture network density was 0.30/cm³.This approach can be popularized to other mines to obtain attributes of 3D fissure network when only 2D data are available.

Key words: CT section image, stereology technology, fissure network, rock fissure, Gejiu tin deposit