Calculation of Stress Concentration in Influence Zone of Mining Face within Gradient-Type Elastoplastic Modeling

Using a gradient-type model, the authors solve a boundary-value problem on stress redistribution in rock mass during mining. The elastoplastic model takes into account local discontinuity. The condition of smoothness of the displacement field is essentially weakened—instead of one smooth field of displacements, two-dimensional kinematics is described using two independent smooth fields. As a consequence, the model receives a structural parameter including the dimension of length and characterizing local bends of unit volumes. The article gives examples of plastic strain calculations in adjacent rock mass with identification of the increased stress concentration zones. It is shown that inclusion of local bends leads, on the hand, to the reduction of plastic shears in adjacent rock mass and, on the other hand, to deeper expansion of high stress concentration zones in rock mass.