Abstract：A numerical model of steady/unsteady flow in fractured rock mass is developed. On the one hand，by using Monte Carlo technique，an intact rock is cut into 3D irregular block elements in term of the statistical distribution of density，orientation，position，size and aperture of fractures. A 3D fracture network is then constructed，which is composed of fracture elements between adjacent rock elements. The hydraulic properties are attached to the fracture elements. On the other hand，the fracture elements are discretized into triangular mesh，and the flow finite element equations are derived based on the variational principle. The dynamic relaxation technique in discrete element method is introduced to solve the permeability field without assembling the global matrix. Finally，the reliability and applicability of the program are validated by typical examples.
