Известия Томского политехнического университета: Инжиниринг георесурсов (Sep 2017)
Protection of artificial arrays from seismic impact at ore underground mining
Abstract
The relevance of the research is caused by the need to find the techniques for protecting artificial filling arrays in blasting at underground mining of metal deposits. The aim of the research is to study the technical possibility to minimize the damaging effect of seismic waves generated by the blast, as a condition for ensuring the safety of operations and improving the quality of extracted ore. Methods: a review of best practices of leading companies, using the results of field and laboratory researches on publication materials, mathematical modeling of technological and economic researches, statistical processing of the data available on the basis of multiple regression and correlation analysis. Results. The authors have systematized the information on application of the methods of controlling the parameters of blasting and crushing ore at the development systems when filling with hardening mixtures. It was determined that mining production facilities are heterogeneous and displacement rates of their structural elements are ambiguous. It was shown that the indices of techniques with hardening mixtures decrease due to ore clogging with the filling material and due to occurrence of technological rock cleavage. The authors proved the leading role of rock seismic vibrations and recommended the method of preventing dangerous seismic vibrations by separation of explosive destruction in time, screening blast waves and controlling breaking options. Conclusions. Mountain massif and the rocks building it up are inhomogeneous; the rates of their displacement at the same blasting conditions are ambiguous. The danger of artificial array destruction with explosive works is the feature of techniques when filling with hardening mixtures. Seismic-explosive waves of the rocks play the leading role in destruction, if the rate of their displacement exceeds the limits. Dangerous seismic vibrations are prevented by separation of destruction processes in time, the most dangerous is the range from 10 to 70 m from the burst point. The artificial array remains stable as long as the voltage at the wave front does not exceed the ultimate strength of the packing material. To maintain safe environment for the array and reduce ore dilution by packing materials the explosion seismic action is controlled by screening blast waves and adjusting breaking options.
