In order to reflect the influence of complex geologic faults in large underground chamber
the authors put forward a numerical simulation and analysis method for the connotative fault element. The method establishes an equivalent element comprising both rock material and fault material
which can decrease the influence of faults incision. By this way
not only the mesh generation of large underground chambers becomes relatively convenient and feasible
but also the influence of complex geologic faults on stability of surrounding rocks is reflected effectively. At last
a sample about underground chamber of Three Gorges Project is given
which testifies that the method is reasonable and provides an effective computation method and train of thought for the analysis of complex geologic faults structure.