ABSTRACT
Air-coupled seismic waves contain a wealth of acoustic information and provide an alternative way to invert explosion source parameters in addition to the precursor seismic waves, which is of great significance. Based on the measured data, this paper analyzed the acoustic-to-seismic coupling characteristics of chemical explosions at a poroelastic site with a sandy soil surface sparsely covered by short vegetation and discussed the change law and quantitative relationships of the arrival time, amplitude, and acoustic-to-seismic coupling coefficient of air-coupled seismic waves. The results show that the sound velocities obtained through theoretical calculations and the arrival time of the air-coupled seismic waves were almost the same as that obtained from the arrival time of acoustic waves, and the particle velocity amplitude of the air-coupled seismic waves had a significant linear relationship with the distance on the logarithmic scale. Additionally, the coupling coefficient of peak acoustic pressure was related to the difference between the attenuation coefficients of acoustic pressure and particle velocity of the air-coupled seismic waves and remained unchanged with the variation of distance as a whole. Through data analysis, it was found that for the coupling coefficients of acoustic pressure peak, Zhalf and ENZhalf were the least discrete on logarithmic and equidistant scales respectively, with corresponding values of 0.57 Pa/(um/s) and 0.34 Pa/(um/s), while for the acoustic-to-seismic coupling coefficients of positive acoustic impulse peak, Z2 and ENZ2 0&1 are the least discrete on logarithmic and equidistant scales respectively, with corresponding values of 0.0081 Pa•s/(um/s) and 0.0047 Pa•s/(um/s).
