Research On Directional Fracture-controlled Blasting And Vibration Reduction Of Shaft Wall By Cutting Seam Cartridge

This thesis takes a shaft in Zhejiang as the research background.From three aspects: the blasting mechanism of cutting seam cartridge,the energy distribution characteristics of blasting vibration signals,and the application of directional fracture blasting with cutting seam cartridge in the shaft,the disturbance and damage to the shaft wall and surrounding rock from the blasting controlled by directional fracture of the cutting seam cartridge were mainly studied.The main work and innovations are as follows:(1)Aiming at the problems of traditional smooth blasting damage to surrounding rock and over-under-excavation,the blasting mechanism of the cutting seam cartridge is studied.When the cutting seam cartridge is blasted,the propagation effect of the detonation product is mainly affected by the wrapping property of the cutting seam pipe and the eccentric uncoupling coefficient.The radius of the crushing zone of the cutting-seam pack is only 60% of that of the ordinary pack,and the radius of the heavily damaged zone is only 81% of that of the ordinary package.The reduction of the crushing zone makes the energy reasonably distributed in the process of rock cracking and forms a good blasting effect.(2)Aiming at the problem of serious damage to surrounding rock based on the smooth blasting of the shaft,the blasting vibration and directional fracture control blasting optimization of the shaft is carried out.When multiple blasting holes are blasted in the cutting seam cartridge,there is only a small range of blasting cracks in the direction of the connection between adjacent blasting holes.The maximum difference between its contour surface and the design contour surface is 0.365 cm.The range of the excavation contour surface formed by traditional blasting is more than 6 times that of the contour surface of the cutting seam cartridge.When adopting the structure of a cutting-seam cartridge,the amount of explosive around the blast holes is reduced by 13.5 kg,which reduces the difficulty and workload of post-cleaning and shipping work,and is more conducive to the post-support and long-term stability of the surrounding rock.(3)Aiming at the problem of blasting vibration signal under special working conditions of the shaft,the energy distribution and energy attenuation law of blasting vibration signal in each frequency band is studied.As the propagation distance of blasting vibration energy increases,the energy distribution tends to be stable and gradually concentrates in the lowfrequency band.The blasting energy of the shaft is consumed more quickly when blasting the near area so that the blasting energy can be applied more concentratedly in the process of rock breaking and reduce the disturbance to the surrounding rock.