Influence of underground mass explosion on protected objects of the industrial site in case of collapse of the interstory whole

Abstract

Within the boundaries of the mining branch of JSC Kyshtymsky MCC the underground large-scale blast was made to cave in the interstorey pillar with the maximum explosive weight 963 kg at the spacing stage. The Institute of Mining of Ural Branch of RAS has received a task to study the seismic impact of the underground large-scale blast on the protected objects of the industrial site of Kyshtymsky underground mine located in the close proximity to the sites of blast works. The aim of the work is to determine the seismic stability of grounds on sites of the protected objects and the permissible values of vibration velocities for buildings of JSC Kyshtymsky MCC. It is also necessary to determine the permissible distances from the blast to the protected objects for 5 engineering-geological elements on the basis of physical and mechanical properties of deposit rocks. On the basis of the initial data, according to the method of the Institute of Mining of Ural Branch of RAS, the authors have performed a complex of calculations of seismic stability of grounds on sites of the objects to determine the permissible values of vibration velocities for buildings of JSC Kyshtymsky MCC. The authors have also performed a multiversion calculation of permissible distances from the blast to the protected objects for 5 engineering-geological elements (EGE) depending on the the explosive weight at the spacing stage, the coefficient of ground conditions and the permissible velocity of seismic vibrations. As a result of comparison of the calculated values and experimental measurements, the recommendations have been given to establish the limitation of the explosive weight at the spacing stage to the level of minimum hazardous values during the large-scale blasts in the underground mine.