Elimination of boundary effect for laminated overburden model in pillar stability analysis

Abstract

The laminated overburden model (LaModel) has been widely used for pillar design and stability analysis. As a boundary element program, the LaModel program is sensitive to the boundary condition, which should be considered before creating the model. To eliminate the boundary effect in a LaModel pillar stability analysis, a suitable boundary buffer zone is needed around the model edge. The radius of influence (R) and the abutment load extent (D) are two major factors that affect the stresses and displacements calculated in LaModel. To determine the optimum buffer zone extent, a database of case histories was analyzed using the LaModel program. Values for R and D were varied until a buffer zone having negligible influence on the pillar stability factor (SF) of the active mining zone (AMZ) was determined.

Keywords

pillar stability / boundary effect / LaModel / numerical simulation / room-and-pillar

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