Fractal fragmentation of weathered rock and its application in engineering geology

Statistical analysis on size distribution of mineral particle of weathered granite is carried out by using fractal method. The results show that the fracture process of weathering is a fractal one. The double logarithmic curves of particle number and particle size are folded lines, and each linear section in the curve corresponds to different fractal dimension. There are at least two fractal dimensions of the particle size distribution of weathered rock, one is the fractal dimension of crystallized mineral particles and the other is the fractal dimension of fractured particles. Based on the test result and theoretical analysis, it is pointed out that the accumulative frequency of particle size distribution has feature of exponential law. The formula for calculating the friable possibility of rock blocks by using exponential coefficient is also presented. Subsequently, the relationship among the shear strength, microstructure and fractal dimension is discussed. Based on the dimension reduction evolution of rock fracturing, the rate of weathering in term of fractal dimension is obtained.