单轴荷载下软砂岩声波传播特性实验研究

We conducted a series of mechanical tests and acoustic measures on Neogene soft sand in order to analysis the diversity of acoustic wave propagation characteristics at different stages. We found that：(1) Velocity, amplitude of the first arriving waves,waveforms,frequency spectrum change with soft sand deformation and relate to the corresponding stages of rock; (2) At the compression and elastic stages of soft sand, the changing trend of longitudinal and transverse wave velocity is consistent with the instantaneous elastic modulus(gradient of the stress-strain curve); while amplitude is consistent with stress; (3) At crack propagation stage, longitudinal wave velocity show weak variation and waves are regular; while transverse wave velocity reduced obviously and waves become irregular gradually; (4) At the failure stage, longitudinal wave velocity changes with the corresponding rock failure process and different failure process results in defferent change ways of longitudinal wave velocity; (5) Longitudinal waves have several frequency domain. The distribution of each frequency domain change little with soft sand deformation ,but the energe of each frequency domain change severely. transverse waves have one main frequenc domain, which maintain the same before breaking. After that frequency domain clutter obviously.