There was a linear relation between fractal factor and minimum wet saturation, which was suitable for both absolute homogeneous and heterogeneous rock.

It assumed that the initial rock stresses is in linear distribution, all layers of strata are regarded as layered homogeneous in calculation districts, and this model is applied to doing calculation.

It lacks liquefied homogeneous layers compared with the preexisting normal succession. This may reflects the fracturing mechanism of the more rigid rock body with higher solidification degree.