Research On The Blasting Seismic Wave Propagating Along Step Topography

Traditional seismic wave propagation theories which will have many big errors are most presented under the condition of the flat terrain, meanwhile, relevant empirical formulas also have limitations. So there will be important realistic significance and research value to study the effect of terrain on the blasting seismic wave, which is useful for exploring seismic wave attenuation rule,predicting and controlling the blasting seismic effect.The laws and characteristics of blasting seismic wave which propagates along the step topography are studied, combined with the field observation experiment and data analysis results. A large number of homogeneous models are established, and the peak particle vibration velocity of step bottom and top are taken as the index to research the change and attenuation rules of particle vibration velocity varies with elevation, then propagation characteristics of blasting seismic wave under the condition of step topography is summarized.In-situ observation data shows that, there is an obvious magnification effect on blasting seismic wave under the step topography. The magnification factors are between 1.15 and 1.41 in the field experiment. When the rock mass structure and fissures are same, magnification factor increases with the increase of the height difference. When the distance increases to a certain value, the effect of height reduced. In the area near explosion, vibration velocity is affected by both distance and height difference, while in the far field vibration velocity is only decided by distance.According to rock physical and mechanical properties and blasting parameters, the propagation characteristics of particle vibration velocity are obtained by simulating, the results has proved that attenuation law of blasting seismic wave under the condition of flat terrain can be well described by Sadov’s formula; The magnification effect on blasting seismic wave presents the increasing tendency first and decreases later; Magnification factor is obviously affected by original energy; Strength of blasting seismic wave is affected by the distance and height difference, through the study of blasting seismic wave attenuation law under the condition of positive and negative height difference, finally vibration velocity prediction model which contains height difference is put forward.