Research On Blasting Vibration Propagation Law And Its Control Technology Considering Elevation And Rock Mass Damage

Blasting vibration,as one of the main harmful effects in the process of blasting operation,is the focus of the research work of relevant scholars at home and abroad.With the continuous development of blasting equipment and engineering blasting technology,large-scale geotechnical blasting engineering in complex environment is more and more common.Therefore,the scientific research and engineering technology field put forward new requirements for the research on the propagation law and control technology of blasting vibration.In order to systematically study the propagation and attenuation of blasting vibration under the influence of elevation and rock mass damage.Based on the monitoring data of several actual blasting projects,the mathematical model of the peak velocity of blasting vibration reflecting the elevation and rock mass damage is deduced theoretically with the method of dimensionless analysis in this paper.On this basis,the method of regression analysis is adopted to compare and analyze the accuracy of various prediction models.It is concluded that the accuracy of the prediction model considering elevation effect is higher and the average deviation is within 7%when the blasting vibration prediction is carried out in the region with large terrain changes.In this paper,it is proposed for the first time that the cumulative damage of rock mass can be characterized by the damage degree of rock mass and the radius of blasting fissure circle.Through the method of non-linear regression analysis,the prediction model of peak velocity of blasting vibration considering rock mass damage under periodic blasting load is obtained.The accuracy of the prediction model is more than 94%.In this paper,ANSYS LS-DYNA software is used to simulate the propagation process of blasting vibration.The propagation law of blasting vibration is analyzed by numerical simulation results.It is concluded that the propagation of blasting vibration has certain elevation amplification effect.By comparing the variation of blasting vibration velocity before and after rock mass damage,it is concluded that rock mass damage has a great weakening effect on the peak velocity of blasting vibration,and the attenuation rate of blasting vibration velocity is 13.302%.Various technical measures for controlling and reducing blasting vibration are also put forward in this paper.Among them,"large-interval delay",optimizing blasting parameters and air interval in borehole have been verified by practical engineering,and the efficiency of vibration reduction is generally more than 30%.It can provide reference for similar projects.