Numerical Simulation Of Sandstone Crushing Process And Determination Of Blasting Parameters Under The Effect Of Loose Blasting

Bench blasting is the main method for rock stripping in an open pit. Compared to other breaking methods, it has some obvious advantages—fast speed, high efficiency, low cost and so on. With the increasing mining intensity and the improving level of mechanization in mining, how to choose more reasonable blasting parameters and more economical blasting cost? Therefore, under the load of loose blasting, the research on rock breakage process and effect is becoming more and more important. Because of different and non-homogeneous rock properties, complex and diverse geological conditions, the traditional empirical data may not play its proper role and value. So the research under loose blasting on rock breakage processes and blasting parameters, which has some theoretical valve and practical significance.At the beginning of this paper, we discussed the characteristics of the numerical simulation, theoretical analysis and experimental study, and made a detailed comparison about their advantages and operability. Livingston blasting crater theory analyzes the formation mechanism of loose blasting crater. Using the nonlinear dynamic FEM analysis software—ANSYS/LS-DYNA, we have simulated the rock blasting processes of intact rock, single jointed rock, a set of parallel jointed rock and different blasting parameters. And got the effective stress of different times in blasting processes, and analyzed their different blasting effect. The main conclusions are: Reflected tensile wave from the free face of intact rock broken rock and formed a set of cracks along the adjacent holes. Joints impeded the normal propagation of stress wave, released energy and emerged large lump. Horizontal group joints were not conducive to the rock breakage, so increased the charge quantity or added holes (in case of a mine in Erdos region). The holes should be located outside of joints in vertical group joints rock.For the different stuff lengths, different hole spacing and row spacing, different hole diameter and different hole layout, we got some y-displacement and y-velocity curves about time history of some elements which from the free face at the top of bench and analyzed their different changing amplitudes. The results showed that the blasting effect of stuff length of 3.2 m, hole spacing of 6 m and row spacing of 3 m, hole diameter of 120 mm,"plum flower"hole layout were better.At last, this paper also collected some pictures from the blasting scene, compared with the numerical simulation results, proved their consistency. What's more, it illustrated the significance of numerical simulation in the design of blasting.