Numerical Simulation Of Preblasting Parameters Optimization

In order to promote the use of mining machine in hard rock, considerate miningmachine was limited by ore-bearing rock strength, we put forward mining machinecombined with the pre-blasting technology in hard rock mine. Pre-blasting is toreduce the effect of rock strength, expanding the scope of the rock internal damage, tosure it suitable for directly mining by mining machine.Durning the process of dynamite blasting, the rock under the action of dynamicfracture experienced a continuous process of damage evolution. Boils down to therock damage fracture mechanism, the stress wave and blasting gas dynamic evolutionthe internal micro cracks gradually grow. If tensile stress of some inside unit in rockgreater than its maximum tensile strength, rock mass would be damaged. In order toidentify the best hole network parameters, combination with the practical productiondata of mine, we put the finite element software ANSYS/ls-dyna to simulate themodle with different hole network parameters, to find out the optimal blastingparameters under different aperture under the blasting damage threshold. Thesisresearch results are as follows:(1) According to the four aperture bore a single, double and three model analysis,double hole model similar model calculation results with the three holes, more canhighlight the damage law of rock mass, and double hole model has the advantages offast calculation.(2) According to the model of double holes blasting simulation under differenthole network parameters, can be obtained under the condition of different damagethreshold value, the experience formula of the percentage of the lesion and holespacing.(3) When damage threshold is certain, with the increase of aperture, holespacing and the aperture ratio tends to fixed value;The minimum resistance line andaperture ratio decreases;Model on the left side of the border to hole area damagewidth and aperture ratio decreases.And the different threshold value under thecondition of hole spacing, the minimum resistance line model and on the left side ofthe border to the hole area damage to the width and the reasonable ratio of aperture. Through the above of pre-splitting blasting hole net parameter optimizationnumerical simulation research, help of pre-splitting blasting technology in a largerscope of application, and provide reference for similar blasting.