Theoretical Calculation And Verification Of Blasting Damage Range Of Cylindrical Charge

At present,some of the basic theories about rock blasting mechanism are based on the phenomenon of spherical packet explosion or experiments due to its proposed age and the limitations of production conditions at that time.In recent years,some scholars have made some achievements in the research work on the explosion damage mechanism of columnar packs,but for the calculation of rock explosion damage,most scholars base on the strength criterion of static damage criterion.In this paper,by summarizing the previous research work,based on the theory of rock explosion dynamics,and considering the influence of loading rate and rock inclusions on rock strength,the Mises criterion is revised to determine the range of blasting damage of columnar charge packages in rock media.In this paper,the dynamic stress field inside the rock body under the action of column pack explosion is calculated,and the column pack is transformed into multiple chain-like spherical packs,and the dynamic stress field of each spherical pack in an infinite rock medium is obtained based on the rock blasting mechanism of the spherical pack.The dynamic stress field of columnar packets was obtained by vector addition method while considering the transfer blast of chain spherical packets.Based on the Mises criterion,the dynamic load strength of the rock mass under the blast action of the column pack was calculated while considering the loading rate and the effect of rock entrapment,and the condition of the rock medium at a certain moment was determined,and the final range of blast damage of the column pack was determined by superimposing the entire damage range during the period starting from the moment0 until the end of the process.A blast funnel test was designed to compare the test results at different hole depths with the volume of blast damage of the columnar pack in a semi-infinite rock medium,and the accuracy was analyzed.