Managing the rock mass destruction under the explosion

Using the theory of elasticity and the main provisions of the quasi-static-wave hypothesis of the mechanism of the destruction of a solid medium under the action of an explosion, analytical modelling of the parameters of the formation of crumpling zones and crushing of the rock mass around the charging cavity during its explosive loading was carried out. Analytical models of the radii of the crumpling, intensive fragmentation and fracturing zones formed around the charging cavity in the rock mass during its explosive loading, taking into account the pressure of the explosion products, the limit of tensile-compressive strength of the rocks, their structural composition, fracturing and compaction under the action of rock pressure, were developed. Based on the change in the stress-strain state of the rock mass under the action of the explosion, numerical modelling of the radii of the zones of crumpling, intensive fragmentation and fracturing was performed using the finite element method. According to the simulation results, the power dependence of the change in the radii of the crumpling and fragmentation zones of the rock mass was determined depending on the diameter of the charging cavity, the pressure of the explosion products, and the limit of rock compressive strength. By comparing the results of analytical and numerical modelling for rigid boundary conditions of a homogeneous non-cracked rock mass, the difference in the values of the radii of the defined zones was established as being 4, 8 and 6%, respectively. The resulting analytical models of the radii of crushing zones, intensive fragmentation and fracturing increase the accuracy of estimating the parameters of rock mass destruction by explosion by up to 50% and improve the parameters of drilling and blasting operations when carrying out mining operations, special purpose cavities and rocking of the rock mass.

Automated summary

This study developed analytical models for the formation parameters of crumpling zones and crushing of the rock mass around the charging cavity during explosive loading, using the theory of elasticity and the main provisions of the quasi-static-wave hypothesis. Numerical modelling using the finite element method was also conducted to determine the radii of the crumpling, intensive fragmentation, and fracturing zones based on the stress-strain state of the rock mass under explosion. Comparison between analytical and numerical modelling results showed a difference in the radii values of 4%, 8%, and 6% for defined zones, respectively. These analytical models improve the accuracy of estimating rock mass destruction parameters by explosion and enhance drilling and blasting operations in mining.