Propagation And Attenuation Of Blasting Vibration Wave Energy Based On Damage Accumulation

With the extensive application of blasting technology in the field of engineering construction,a series of harmful effects caused by blasting vibration on surrounding buildings and buildings have attracted more and more attention.Because of the complexity of engineering construction,the blasting operation is not always completed under one action,but the result of repeated repeated explosions,which is bound to cause damage to the surrounding structures.Therefore,it is of great significance to analyze the cumulative damage rule of rock mass propagation and attenuation law of blasting vibration wave energy under repeated blasting.Article the energy variation characteristics of blasting vibration wave based on damage accumulation are studied by combining theoretical analysis and laboratory test,get the following conclusions:(1)Potential and indirect disturbances of explosion stress waves and explosion gases is the result of blasting vibration damage accumulation,first internal microcracks native rock tip produce localized damage due to stress concentration effect,and generates a certain number of newborn microcracks,subsequently,the microcracks propagated to form meso-cracks,and the deterioration of rock mechanics parameters increased,the micro crack propagation through macroscopic cracks,rock integrity and sharp reduction of bearing capacity.(2)Blasting vibration damage with the increase in the number of blasting vibration effect continues to increase,blasting vibration cumulative presence of a cubic polynomial function of the relationship between the damage and the number of cycles than blasting,blasting vibration damage accumulation process can be divided into slow growth,rapid growth and rapid mutation.(3)Decrease continuously with the increase of blasting times the peak vibration velocity and main frequency;for single blasting of blasting vibration,the faster the peak velocity decays from the explosion source;with the increase of the number of blasting,the results show that the decrease of the measuring point in the near area is larger than that in the middle distance.In the far and middle area,there is no obvious change in the velocity of vibration when the number of blasting is few,in the late stage of blasting,there is a sudden increase in the vibration speed at each measurement point.(4)Packet analysis calculation of the measured vibration signal energy of each frequency band is calculated by wavelet analysis,with the blasting distance increases,the main vibration frequency of blasting vibration signals are mainly concentrated in the low frequency region;with the increase of the number of blasting vibration signal features,the performance for the initial change is not obvious,when the damage accumulates to a certain the degree of low-frequency energy concentration changes obviously,because of building the free vibration frequency is low,which is likely to cause serious damage effect.By carrying out the research on the cumulative rule of vibration damage during multiple blasting of concrete,the theoretical and experimental basis for the post-blast blasting safety assessment and vibration hazard control based on the cumulative damage is established.