Abstract The article describes an experimental study, which aims to detect signs of jump-like inelasticity in sandstone and to establish their influence on the P-wave attenuation. The measurements were taken in a sandstone sample using the reflection method at a pulse frequency of 1 MHz and with the strain amplitudes e 1 ≈ 0.1 microstrain and e 2 ≈ 0.24 microstrain at a hydrostatic pressure of 10 MPa. Using the high-resolution recording of the acoustic signal, the short-period low-amplitude oscillations were detected in the waveform and were interpreted as manifestations of jump-like inelasticity. These unconventional manifestations have forms of a stress plateau and a stress drop. At all strain amplitudes, with an increasing frequency in the range of (0.5–2.0) MHz, the P-wave attenuation in the sandstone sample monotonously increases and has a peak at a frequency of ∼ 1.56 MHz. The jump-like process is amplitude-dependent; it introduces changes in the attenuation peak parameters. The simple simulation demonstrated considerable variation in the attenuation peak magnitude (from 0.353 to 0.607) due to this effect. The jump-like deformation process in rocks can presumably be explained by the combined action of the viscoelastic and microplastic mechanisms. The results of this study can be useful for improving the methods of geological interpretation of seismic and acoustic data.

中文翻译：

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砂岩中的跳跃状非弹性及其对纵波衰减幅度依赖性的影响：实验研究

摘要 本文描述了一项实验研究，旨在检测砂岩中跳跃式非弹性的迹象并确定它们对纵波衰减的影响。测量是在砂岩样品中使用反射方法在 1 MHz 的脉冲频率和应变幅度 e 1 ≈ 0.1 微应变和 e 2 ≈ 0.24 微应变下在 10 MPa 的静水压力下进行的。利用声信号的高分辨率记录，在波形中检测到短周期低振幅振荡，并将其解释为跳跃式无弹性的表现。这些非常规表现具有应力平台和应力下降的形式。在所有应变幅度下，随着频率在 (0.5–2.0) MHz 范围内的增加，砂岩样品中的 P 波衰减单调增加，并在约 1.56 MHz 的频率处出现峰值。类似跳跃的过程是幅度相关的；它引入了衰减峰值参数的变化。简单的模拟表明，由于这种影响，衰减峰值幅度（从 0.353 到 0.607）发生了相当大的变化。岩石中的跳跃状变形过程大概可以用粘弹性和微塑性机制的共同作用来解释。本研究结果可用于改进地震和声学数据的地质解释方法。353 到 0.607）由于这种影响。岩石中的跳跃状变形过程大概可以用粘弹性和微塑性机制的共同作用来解释。本研究结果可用于改进地震和声学数据的地质解释方法。353 到 0.607）由于这种影响。岩石中的跳跃状变形过程大概可以用粘弹性和微塑性机制的共同作用来解释。本研究结果可用于改进地震和声学数据的地质解释方法。