Study On The Influence Of Different Size Resistance Lines On The Attenuation Of Blasting Seismic Waves

The blasting seismic waves generated by the explosives exploding in the rock mass media will cause the rock mass particles and the surface to vibrate,which in turn will cause the blasting seismic effect,which will not only cause unnecessary waste of explosive energy,increase the economic cost,but also affect the step slope Damage to buildings and structures.In engineering blasting,the size of the resistance line is not only related to the quality of the blasting effect,but also directly affects the propagation law of blasting seismic waves.At present,most of its research is based on field production tests,ignoring the difference between the rock mass media.Uniformity and anisotropy.Therefore,in order to accurately study the attenuation law of blasting seismic waves by different resistance lines,this article uses the similarity theory as the basis,derives the similarity criterion that the model test should follow by using the dimensional analysis method,and establishes concrete models of different size resistance lines for single-hole blasting test.Then use origin data analysis software and HHT analysis method to analyze the blasting seismic wave attenuation from the perspective of vibration speed and energy,and obtain the blasting vibration attenuation formula,IMF component,instantaneous energy spectrum,three-dimensional energy spectrum and marginal spectrum.Through comparative analysis,The influence of different resistance lines on the attenuation law of blasting seismic waves was obtained.Finally,the field test verifies the conclusions obtained from the model test,which has certain guiding significance for reducing blasting vibration and improving energy utilization.The main contents and conclusions are as follows:(1)The attenuation law of blasting vibration speed has a direct relationship with the size of the resistance line.The main manifestation is that as the resistance line increases,the peak velocity of the blasting vibration particle also increases,the speed decays more slowly,and the X direction The main frequency has a trend of high frequency concentration.(2)With the increase of the blasting center distance,the peak velocity of the blasting vibration particle gradually decreases,and the main frequency has a tendency to change towards the low frequency concentration.In the near area of the blasting,the peak velocity in the X direction decays rapidly,and the attenuation in the Y and Z directions is more It is gentle,and the decay of instantaneous energy has the same trend as speed.(3)Through linear regression analysis of blasting vibration monitoring data of different models,the blasting vibration velocity attenuation formulas of the three models are obtained.Comparing the attenuation formulas of different resistance lines,it can be found that the attenuation coefficient ? value of the peak velocity of the particles in the three formulas gradually decreases,Indicating that with the increase of the model resistance line,the attenuation of the peak velocity of the blasting vibration particles gradually slows down.(4)Under the same explosive amount,the theoretical wave energy percentages of model 1,2,and 3 were calculated by theoretical calculations to be 3.38%,5.76%,and 8.64%,respectively.This result shows that the seismic wave energy conversion of the blasting test with a large resistance line The rate is high,the energy loss is large,that is,the energy utilization rate of the large resistance line is low.This enlightens us that in order to reduce the energy of blasting vibration and improve the energy utilization rate of explosives,the parameter design of the blasting hole network should be optimized to increase the energy ratio of explosives to break the rock medium.(5)By using the HHT analysis method to obtain the IMF components,instantaneous energy spectrum,three-dimensional energy spectrum,and marginal spectrum of the three models at different positions,the energy distribution characteristics at different positions,different moments,and different frequencies can be presented intuitively.It reveals the influence of different resistance lines on the energy attenuation of blasting seismic waves.(6)Through the analysis of the field test monitoring data,it is found that the blasting vibration velocity,main frequency,and energy attenuation changes obtained from the field test are in good agreement with the conclusions obtained from the concrete model test,which verifies the correctness of the conclusions obtained from the model test At the same time,the conclusions obtained have certain guiding significance for actual production.