Abstract: Rock fractures are assumed as “filled medium”, which enables to treat the rock fractures with or without fillings coincidently. The relationship between the stiffness coefficient, hydraulic conductivity coefficient and the normal effective stress is deduced. Based on the principle of the block element method, seepage-stress coupling model for three dimensional fractured rock mass is built by using the iterative algorithm between the two fields. It treats the blocks as rigid and imperviousness bodies, and the displacement and seepage just mainly happens in fractures. The corresponding program is also written by Fortran language which integrates the stress analysis module and seepage analysis module together. This improves the computational efficiency. Lastly, the Shatuo gravity dam is simulated to verify the proposed method. The most advantage of this model is that large-scaled joints and random fractures are considered; and the preprocessing & post-processing are simple.

Key words: rock mass, random fractures, seepage-stress coupling, block element method