对饱和泵油南京砂岩和饱水大理岩在MTS上进行了单轴压缩实验和正弦波加载实验,求得两种饱和岩石的单轴抗压强度和屈服强度,并获得随正弦波频率的提高,饱和泵油南京砂岩的杨氏模量、纵横波速度增大,具有较明显的频散效应。饱和岩石中的微细观缺陷在正弦波加载中引起滞后,导致瞬时杨氏模量与应力成不对称"X"形,获得随正弦波频率增高,"X"交点在模量轴上的位置增高,杨氏模量增大,模量的频散增强。本文揭示了岩石的非线性时频响应的一些物理机理,对于岩石介质中的非线性波动研究以及地震、工程等理论研究和应用都具有重要意义。
Uniaxial compression experiments and sinusoidal loading experiments were carried out on MTS for pump-oil saturated Nanjing sandstones and water saturated Dali marbles. Uniaxial compressive strength and yield strength of both saturated rocks were obtained. Young's modulus and velocities of longitudinal wave and transverse wave increase with sinusoidal wave frequency with notable frequency dispersions. The hysteresis due to the existence of micro defects in saturated rocks in sinusoidal loading experiments results in the variation curves of instantaneous Young's modulus with stress for loading and unloading intersection, therefore an "X" shape figure is obtained. As the frequency of sinusoidal wave increases, the position of intersection point moves to higher modulus area and the modulus dispersion increases. Some physical mechanisms of nonlinear frequency response of rock are revealed. These obtained results are very important to study of nonlinear wave in rocks and theoretical analysis and application of earthquake and engineering.