Investigating the seismic impact made by the underground large-scale blast on the secure facilities of Kyshtym GOK when caving the floor pillar

Abstract

Introduction. Within the mining claim boundaries of Kyshtym GOK the underground large-scale blast was made to cave in the floor pillar with the maximum explosive weight of 963 kg at the spacing stage. The Institute of Mining UB RAS has received a task to study the seismic impact of the underground large-scale blast on the secure facilities of Kyshtym underground mine industrial site located in the close proximity to the sites of blast works. Research aim is to determine the seismic stability of grounds at the sites of the secure facilities and the permissible values of vibration velocities for Kyshtym GOK buildings. It is also necessary to determine the permissible distances from the blast to the secure facilities for 5 engineering-geological elements on the basis of physical and mechanical properties of rock. Research methodology. On the basis of the initial data, according to the method of IM UB RAS, ground seismic stability calculations have been made at the sites of the facilities to determine the permissible values of vibration velocities for Kyshtym GOK buildings. A multivariate calculation of permissible distances from the blast to the secure facilities for 5 engineering-geological elements (EGE) has also been made depending on the explosive weight at the spacing stage, the coefficient of ground conditions and the permissible velocity of seismic vibrations. Results. The actual velocities of earthquake vibrations were determined by the results of experimental measurements using Minimate Plus and URAN seismic recorders, the values of which did not exceed the permissible velocities of ground motion in the base of buildings. Summary. As a result of comparing 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.