Moreover, meaningful differences in the stability analysis results between the three stress scenarios highlight the importance of appropriate selection of stress estimation approaches in planning deeper mine levels. The results demonstrate that in spite of the development of extensive brittle and tensile damage zones within the rock mass, no major brittle or tensile failure is expected to occur at the considered mining levels based on all three stress scenarios. Numerical modeling ( FLAC3D) was used to evaluate the potential of brittle, tensile and compressive failure for the vertical transverse and rib pillars. Three different scenarios for estimating stress at the Niobec underground mine (Quebec, Canada) were determined based on the data available from previous stress measurement campaigns. The influence of different in situ stress judgement on the deformation and failure characteristics of the Bukov Underground Research Facility (URF) (Phase II, Czech) were investigated by the finite volume program FLAC3D. Each scenario could yield different stability assessment results some of which were not normally used in the current mine stability study. in principal stress ratio and mean stress values obtained from four different measurement/analysis campaigns.
These interpretations could produce several scenarios for estimating the stresses in a mine. The in-situ stress values that are used in the evaluation of the stability of underground structures in each mine strongly depends on the results of measurement of the stresses as function of the mine depth and the methodology used for the interpretation of the data as well as engineering judgment. However, significant uncertainties are associated with the estimation of these parameters.
In deep underground mines, a successful development plan to exploit deeper mining levels is highly dependent on adequate consideration of the magnitude and orientation of situ stress state.