Substantiation of wave resistance of composite materials for protecting underground workings against elastic vibrations

Abstract A model of calculating parameters of the means for protecting an underground structure from stress waves during an explosion was developed. Various types of polymers from the German manufacturers MC and Carbo were studied as the material for this means, and their properties - wave damping coefficients and wave resistance- were determined. The path of the wave propagation from the center of the explosion to the support of the underground structure was analyzed taking into account the wave damping and refraction when passing through rock layers and polymer protective means. The critical velocity of displacement of rocks on their contour, which is regulated by regulatory documents, serves as a criterion for the stability of structures. Analytical formulas for determining this velocity at an explosion on the day surface and at an underground explosion were obtained. Based on the results of the calculations, the parameters of the protective polymer layer (its thickness and wave resistance) are substantiated depending on the initial wave velocity at the boundary of the transition from inelastic deformations to elastic ones.