Theoretical Research And Numerical Simulation Of Control Blasting Technology For Nearby Slope

Presplit blasting is a technical measure often used in controlled blasting near the slope.It has been used in deep open-pit mines and hydropower stations and other high steep slopes,in order to obtain a smooth rock wall and avoid excessive excavation,owed Digging phenomenon to achieve the desired blasting effect.Especially in the field of control blasting in open blast mines where there is a large amount of blasting rock and explosives used,the use of presplit blasting technology not only weakens the vibration of the blast to the slope,but also reduces the maintenance cost of the slope in the later period,and also reduces the Vibration of nearby buildings is harmful.By using ANSYS/LS-DYNA,two-dimens ional two-hole uncoupled media with different non-coupling coefficients under different numerical conditions of charge blasting were established,and the stress development process of uncoupled charge blasting was reproduced,and the blasting stress cloud diagram and stress time were obtained.The graphs of the curves show that the different coupling coefficients of the decoupled charges in air and water media are different,and the differences in the attenuation rates of water and air to the stress are compared,and the midpoint elements of the two holes are analyzed as the damage analysis objects.The numerical simulation results show that the pre-splitting blasting achieves the best blasting effect when the hole spacing is 250 cm and the radial coupling coeffic ient of the water is not 2.5,and the velocity of the surface unit at the midpoint of the line connecting two holes of the uncoupled charge is passed.Time-history curve analys is shows that the pre-splitting blasting technology of water-medium uncoupled charge has a better shock absorption effect,which has a good effect on maintaining the safety and stability of high and steep slopes.According to the actual production situation of Daye Iron Mine in Wuhan Iron and Steel Corporation,pre-splitting blasting was performed on two different methods of loading the uncoupled medium,and the overall blasting results were satisfactory.However,from the slope after excavation of the electric shovel,it was found that the flatness and half-hole porosity after presplit blasting of the water medium were better than those of the air-medium uncoupled presplit blasting,and it was found that the slope did not appear to be over-excavated or owed.Digging phenomenon,this way of charging greatly reduces the maintenance costs of the slope,and plays a decisive role in the economic benefits of the mine.In addition,it has been found that the use of water as an uncoupled medium also has the advantage of reducing the ground peak velocity,which is greater than the non-coupled charge of air media,and it also has better results in terms of dust reduction and shock reduction.Therefore,the technical results of the pre-splitting blasting method for water-medium non-coupling charges are advocated for use in such mines.