عنوان مقاله [English]
Subsidence is one of the inevitable phenomena of most underground mining and excavations, especially in long-wall mining methods (i.e. in filling, with out filling and mechanized long-wall methods). It may also occur in room and pillar mining methods (i.e. in both with and without pillar recovery methods). Subsidence phenomenon occurs due to some vertical and horizontal displacements of the ground surface located just above the excavated area. This may also in turn causes surface destructions and eventually result in irretrievable loss of life and property. In this study, a higher order displacement discontinuity method (HODDM) which is a subdivision of the boundary element method (BEM) was used to model the subsidence. To be able to evaluate the horizontal strains on the surface of the excavation the finite difference method (FDM) is also added to the proposed numerical method. The vertical displacement and the horizontal strain (relative displacement) of the ground surface of the excavating area can be evaluated by this modeling technique. It should be noted that, subsidence due to the mining of both horizontal and inclined (oblique) layers were considered in this study. Some of the numerical results are compared with their corresponding empirical ones given in the literature. This comparison shows a good agreement between the numerical and empirical results.