Abstract：In order to expand the applicability of the coupled fictitious stress method and displacement discontinuity method，an advanced numerical system FSM·DDM that can be applied to the problems dealing with rock bolting is developed. In the procedure，two line elements representing rock hole and rock bolt are taken into consideration. Basic condition of this system is displacement continuity over the hole length of two line elements which have the same geometry，i.e. the two line elements are overlapped. The condition mentioned above corresponds to the real condition that rock bolt surface completely adheres to borehole wall. Hence，the displacement difference between two ends of bolt element is equal to that of borehole element in the numerical procedure. The influential coefficients due to extension of line element are computed based on Kelvin solution. Then，the borehole line element(free element) is combined to the three-dimensional BEM system with rock bolt line element，and the combined system can be solved as a boundary value problem.
