Determining the Magnitude of Rock Pressure on the Underground Mine Working Support

Abstract

This paper considers a method for determining rock pressure using standard strength characteristics determined during engineering surveys – uniaxial compression strength R_c for rocky soils and strength parameters of the ideal elastic-plastic Coulomb-Mohr model (angle of internal friction of the soil φ and specific soil adhesion c) for dispersed soils. Within the framework of the proposed methodology, the existence of critical heading spans was established that determined the need for its fastening or transformation of the form of loss of stability of the rock mass from the collapse arch to the collapse column. In addition, a static solution of the theory of limiting equilibrium of soils as applied to dispersed soils was obtained in the paper. A hypothesis is formulated about the fundamental correspondence between the behavior of soils that exert active pressure on the enclosing structures and the behavior of soils that create rock pressure on the supports of underground workings. Therefore, the static solution on rock pressure is based on the well-known solution used to determine the magnitude of the active pressure on the structures of underground and buried facilities: the enclosing structures of pits, retaining walls, etc. A numerical example was calculated, a field of limiting stresses was constructed, characteristic lines were determined, and the value of limiting pressure was calculated. Previously, the authors of this work carried out theoretical studies to determine the rock pressure [1, 2].