Study on fractal dimension of discontinuity distribution based on simulation technique of discontinuity network

The fractal concept and the fractal characteristics of rock masses are discussed in general. The box dimension method is studied based on the technique of network simulation, and a calculation sample of fractal dimension for the engineering rock masses in Three Gorges Reservoir region is given. The problem of proper range of box size is discussed. Various factors, such as fracture space, total length of discontinuities, and inclination between joints, are analyzed. The results show that the space of discontinuities affects fractal dimension markedly. It is certain that the index of fractal dimension is better than the index, RQD, on characterizing jointed rock masses and classifying engineering rock masses. At last, some problems on the range of box size and the relationship between fractal dimension and engineering properties of rock masses are pointed out for further study.