Abstract: The identification and analysis of geotechnical mesocharacteristic play a crucial role in the study of rock and soil mechanics. Based on the principles of Fourier transform, a two-dimensional outline of rock and soil particles can be transformed into Fourier descriptors and phases, and then a mesocharacterization method is established based on plural Fourier analysis. The corresponding relationships between different orders Fourier descriptors and mesocharacteristic parameter are investigated through counting Fourier mesocharacteristics of two groups of different particles. It is shown that the Fourier descriptors corresponding to -12-0 and 16-20 orders determine the shape of particles, and the Fourier descriptors corresponding to -23--11 and 1-15 orders are closely connected with the roughness of particles. There exists a significant linear correlation between the peak value of Fourier descriptor curve and the particle size of rock and soil particles. High-order Fourier coefficient and its order are approximately in a logarithmic linear relation, however, low-order coefficient is determined by different particle shapes. By using the established Fourier descriptor corresponding relationship, particle similarity remodeling is studied. It is shown that the outlines and Fourier statistical parameters of remodeled particles are very close to the actual particles, and the remodeled particles can reflect the mesocharacteristics of particles such as roughness and texture. The method can be used for the study of correlation between a large number of rock and soil particles and their mechanical properties.

Key words: rock and soil particles, mesocharacteristic, plural Fourier analysis, random reconstruction