Detection of acoustic pulses in river sand: Experiment

Experimental results on the parametric generation and propagation of low-fr equency video-pulse signals formed as a result of the detection of high-fre quency acoustic pulses in dry and water-saturated river sand are presented. The dependence of the propagation velocity of video pulses on the static p ressure, the dependence of the video pulse amplitude on the amplitude of th e pumping wave, and the relation between the shape of the detected pulse an d the envelope of the pumping pulse under different static loading of the m edium are studied experimentally. Nonlinear equations of state adequately d escribing the observed phenomena in dry and water-saturated sand are obtain ed on the basis of the analysis of the experimental results.