Fractal evolution of a crack network in overburden rock stratum

A quantitative description for the spatial distribution and the evolution o f a crack network in mining rock stratum is one of the most difficult and f undamental problem in the subject of surface subsidence. In this paper, the physical models are employed to simulate the spatial distribution of a cra ck network. By using the fractal geometry, the self-similarity of spatial d istribution of crack network is discovered. As a result, the conception of fractal crack network is proposed. Furthermore, the evolution of a crack ne twork with the increasing of mining width is investigated. It is shown that (1) the spatial distribution of a crack network displays the fractal behav ior, so, the fractal dimension can be used to describe quantitatively the e volution of the crack network, (2) the fractal dimension of the crack netwo rk increases with increasing of mining width, (3) the surface subsidence in creases with the increasing of fractal dimension of crack network.