The mechanics of plastic volumetric deformation of rock and the rockburst mechanism

Abstract

Relevance and problematics. The problem of rock pressure dynamic manifestations, primarily rockbursts and tectonic shocks, is particularly acute for both coal fields and ore deposits. Dynamic manifestations of rock pressure lead to injury and death, to kilometers of destroyed mine workings, loss of minerals, business interruption and additional costs for forecast and prevention. However, these geomechanical phenomena seem to be the most unexplored. They have been studied purely at the empirical level. This is due to poor understanding of the elastic energy accumulation and release mechanism in dynamic phenomena. Methods of research. The proposed model of plastic deformation of rock and the resulting mechanism of rockbursts and tectonic shocks, impacts and earthquakes are based on analytical criteria for rock plasticity and strength, confirmed by a large amount of experimental data. Results, their analysis and recommendations for use. Based on the previous studies performed by the author, a new model of plastic deformation of rocks at the stage of deformation strengthening is proposed. Based on this model, the mechanism of rock plastic deformation, the mechanism of fractured block media destruction and accumulation of deformation energy by rocks are substantiated. It is shown that blocks of various ranks turning leads to deformation energy accumulation in the rock mass. The energy is accumulated both in the blocks and in the surrounding. Conclusions. The proposed model of rockburst and other dynamic phenomena, as well as block mass strength criterion, made it possible to obtain a burst hazard criterion in an analytical form for the first time. The fracturing (blocking) role and contribution to the rockburst mechanism has been shown for the first time. Comparison of the proposed burst hazard criterion with an empirical analogue shows good convergence.