Analysis On The Vibration Isolation Effect Of The Damping Hole On The Rayleigh Wave During Blasting

How to reduce the disadvantages caused by blasting vibration is one of the concerns by many people in the blasting projects.On the basis of theoretical analysis,the author briefly made a study on the vibration isolation mechanism of the damping hole on the blasting seismic wave.Used the MATLAB software to create relevant programs to calculate sizes and related parameters of the damping hole in elastic half-space and analyze their effecting rule on the vibration-reduction effect.In this paper,many project examples were used to test the correctness of these calculation programs.(1)The mechanism and classification of blasting seismic wave were theoretically analyzed based on the continuous medium theory.Wave velocity expression of blasting seismic wave is studied.After established the rock medium coupling wave equation,the Helmholtz decomposition was adopted to explain the wave equation in the rock medium,concluding the attenuation expression of all body types.(2)Through the introduction of the vibrating isolation mechanism of damping holes on the blasting seismic wave,the mechanism of interaction between blasting seismic wave and damping holes were studied in this paper.The damping effect of single vibration damping hole in infinite elastic plane was deduced and analyzed to introduce the expression of incident wave and reflected wave,Combined with displacement,stress and boundary conditions,the expression for damping effect of single vibration damping hole can be obtained through the expansion method of wave functions.The influence law of the aperture and the medium passion’s ratio on the damping effect is produced.(3)On the basis of elastic-body semi-analytical boundary element method,the boundary element equation of damping effect in elastic half-space was obtained.Meanwhile,correlation calculation program was built by MATLAB to calculate and analyze the damping effect of double row quincunx damping hole on Rayleigh wavein blasting seismic wave.If the quantity of holes is fixed,increase of the diameter of hole and depth of vibration-reduction can improve the vibration-reduction effect;and the decrease of the spacing and row spacing among holes also can improve the effect.If the size and quantity of the vibration-reduction are fixed,compared with the low frequency,the vibration-reduction effect of the double row damping holes on the high frequency Rayleigh wave would be better,and the correctness of the programs could be test through the monitoring data in actual projects.