Experimental Study On The Attenuation Law Of Blasting Stress Waves With Different Charge Structures

In this paper,we study the different charge blasting stress wave in the transmission characteristics of rock structure,according to different charge structure,the use of dynamic strain collection system collected coupling continuous charging structure and coupling discrete charge structure,no coupling continuous charging structure,not coupled discontinuous charge blasting stress wave in rock characteristics of the changes in the structure,analyzes the different charge structures the attenuation law of stress wave,The attenuation rate of different charging structures in the rock was obtained by calculation,and the change of sound velocity in the rock before and after blasting was detected by rock acoustic side detector to judge the damage inside the rock.Finally,the blasting stress wave of different charging structures was analyzed by numerical simulation.The main conclusions of this paper are as follows:(1)The stress values of the four charging structures are exponentially attenuated at the radius 0?20 times of the axial distance from the borehole.The stress values of the four charging structures are linearly varied at the radius 30 times of the borehole.The stress wave attenuation is not obvious,and the peak stress is the largest at the radius 10 times of the axial distance from the bottom of the borehole.(2)The initial stress peak of the coupling continuous charge structure is the largest,the initial pressure and the maximum pressure of the borehole wall are the largest,the borehole wall is excessively crushed,the borehole pressure decays quickly,and the detonation wave acts on the rock mass for a short time;The initial peak stress of the uncoupled charge structure is small,and the detonation wave passes through the uncoupled medium with strong compress,which reduces the initial pressure of the hole wall,avoids the excessive crushing of the hole wall,and the pressure attenuation in the hole is slow,thus prolonging the action time of the detonation pressure.(3)according to the acoustic change,coupling continuous charging structure crush zone in 0 ? 10 radius,fracture zone within a radius of 10 ? 20 times,the rest of the three kinds of charging structure crush zone in 0 ? 5 times the radius of fracture zone within a radius of 5 ? 20 times,no coupling continuous charging structure fracture zone is the largest,not coupled discontinuous charge structure crush zone is minimal.(4)the coupling charge structure in the broken area spend a lot of energy,rock broken zone is bigger than non-coupling charging structure with conditions,and the energy transfer is not uniform,although not coupling charge structure broken zone,but the scope is small,and stress wave attenuation slower,energy transfer and uniform,consistent after blasting in rock,therefore,in real life should implement non-coupling charging structure.