Grain size analysis of glacial deposits based on digital image processing technology

To a great extent，granularity composition controls the physical and mechanical properties of glacial deposits, but continuous granularity composition could not be obtained by conventional geotechnical test. Technical method on the combination of digital image processing with laboratory test is introduced in the paper, the processes of which are as follows: firstly, granularity compositions of coarse grain (>20mm) in glacial deposits are obtained by using digital image processing; then, the granularity compositions of matrix (<20mm) are obtained based on laboratory test; finally, the continuous granularity compositions are obtained by combining the above results. Based on fractal and fractal dimension theory, the granularity characters, the directional dimension of rock blocks and the configuration characters are analyzed. The results indicate that glacial deposits have a nice character of self-comparability in statistics.