In order to assess the strength, integrity and stability of a fractured underground excavation subjected to seismic and blast waves, a dynamic analysis of the displacement and stress fields around the excavation is carried out using a boundary integral equation (BIE) approach with a slip model of fracture. This paper outlines the approach and presents results of preliminary parametric studies. The results indicate that an intersecting fracture redistributes and usually amplifies the stress along and around the surface of the cavity. For certain combinations of the parameters, the stress amplification and complication can be very significant. It is found that the strongest stress concentration and deformation do not occur when the traction on the fracture is free but occur when the frequency dependent normalized slip stiffness parameters are of moderate values.
展开▼
