ESTIMATION OF SEISMIC LOAD OF BLASTING ON PIT WALL ROCK MASS DURING BLASTED SLOT MAKING
Based on 2D elastoplastic numerical modeling, the process of blasted slot making during perimeter control blasting of decoupled charges with radial gaps filled with air and water is studied. The stress field patterns under blasted slot making are obtained, and the field of effective radial and shearing stresses in the near range of explosion is investigated for the conditions in question. From the results of the accomplished numerical experiments, the variation in the radial and shearing stresses and in the values of PPV in the pit wall rock mass is determined as function of distance from blasted slot. It is found that the perimeter control blasting in the presence of water in holes results in considerable change in the stress state in the pit wall rock mass in the blast near zone, which should be taken into account when ma king blasted slots. The screening effect of the made blasted slot during pit wall blasting is estimated. It is illustrated that the application of the pre-fracturing method is an efficient tool of reduction in seismic load of blasting on pit wall rock mass.
: Kamyansky V. N.
Kamyansky V.N., Graduate Student, e-mail: firstname.lastname@example.org,
Mining Institute of Kola Scientific Centre of Russian Academy of Sciences,
184209, Apatity, Russia.Key words
Numerical simulation, finite element method, blast, contour blasting, pre-split blasting.References
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