| The mining industry is an important foundation for my country's economic construction and the development of other industries.The vast majority of open-pit mines often choose controlled blasting technology to solve the impact of blasting construction on slope stability.This technology can better complete the pre-cracking effect on surrounding rock.control.Adjusting and optimizing blasting parameters in controlled blasting can improve mining and production efficiency,enhance slope stability,and effectively reduce the investment in slope maintenance,so as to achieve more ideal production and economic returns.In this paper,the parameters of pre-splitting blasting and smooth blasting are optimized by theoretical analysis,numerical simulation and field tests,and applied to engineering problems,and the expected results are achieved.This paper optimizes the parameters of pre-split blasting and smooth blasting through theoretical analysis,numerical simulation and field test,and applies them to engineering problems to achieve the expected results.The main conclusions of this article are:(1)The cracking principle of pre-splitting and smooth blasting is summarized.The action mechanism of blasting load is summarized.Summarize the cracking principle of pre-splitting and smooth blasting;summarize the action mechanism of blasting load;study the width of pre-cracking;analyze in detail the different situations of pre-splitting two holes;determine the pre-splitting blasting parameters And discussed the relationship between the main blasting parameters;analyzed the quality control of pre-splitting and smooth blasting.(2)Three types of blasting hoppers were successfully simulated using ANSYS/LS-DYNA finite element software.The blasting exponents n of the enhanced throwing,standard throwing and loosening blasting hopper are 1.37,0.92 and 0.7.The actual charge of different blasting hoppers is obtained by substituting the empirical formula.The numerical simulation results are consistent with the objective reality,the simulation in this article is correct,and the mechanism of rock fragmentation is verified.(3)Use finite element software to simulate working conditions with different non-coupling coefficients.Two types of rock failure are established based on the stress curve of the rock monitoring point unit,that is,the two types of damage caused by stress wave action,stress wave and explosive gas.Combining the criterion of cracking between two holes,the best non-coupling coefficient is 2.5;by comparing the rock stress cloud diagrams under the spacing of each hole,combining the criterion of cracking between two holes,the diameter of the cartridge is 35 mm,and the diameter of the blast hole is 35 mm.It is 88 mm,and when the hole spacing a=90-100 cm,the effect of pre-cracking is better;the process of rock failure by smooth blasting is analyzed.Through the velocity,acceleration and displacement time curves of the monitoring points of the rock unit,the process of rock throwing at different distances from the free surface is analyzed in detail.Combining the criterion of forming a seam between two holes,Optimal proximity coefficient for smooth blasting m=1.By simulating the interval initiation with different initiation time differences between the two holes,the simulation results show that: crack.(4)Based on the results of numerical simulations,pre-split blasting tests were carried out on different platforms of Phoenix Mountain to optimize blasting construction parameters.The effect of pre-cracking can be judged by observing the condition of the side slope wall,counting half porosity and slope flatness.The test results show that when the pre-splitting blasting non-coupling coefficient k=2.57 and a=80 cm,the smooth blasting proximity coefficient m=1,and there are no over-excavation and under-excavation problems in the slope area.Applying the optimized parameters to other platforms has also achieved good expected results.The error between numerical simulation and field operation is not big,indicating that numerical simulation is feasible... |
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