Kimura Masao
School of Marine Science and Technology, Tokai University, 3-20-1 Orido, Shimizu-ku, Shizuoka, Shizuoka 424-8610, Japan.
J Acoust Soc Am. 2008 May;123(5):2542-52. doi: 10.1121/1.2902179.
The author has proposed a modified gap stiffness model, which is incorporated into the Biot model; the resultant model is called the BIMGS model. By using this model, it is theoretically demonstrated that the frame bulk modulus is dependent on frequency [M. Kimura, "Frame bulk modulus of porous granular marine sediments," J. Acoust. Soc. Am. 120, 699-710 (2006)]. In this study, the modified gap stiffness model is reinvestigated and approximated expressions are derived for low- and high-frequency ranges. In particular, experimental validation of the BIMGS model is carried out. First, for glass beads and beach sands, the modified gap stiffness at a high frequency is experimentally obtained as a function of the grain size. Second, by using the measured values of the longitudinal wave velocities in the glass beads with two types of alcohol-water-mixed liquids, it is validated that the frame bulk modulus is a linear function of the fluid bulk modulus and that the frame bulk modulus is dependent on frequency, which can be derived from the BIMGS model. Finally, for applying the BIMGS model, it is shown that the reported velocity dispersion and the frequency dependence of attenuation, which cannot be explained by using the Biot-Stoll model with a constant frame bulk modulus, can be explained.
作者提出了一种改进的间隙刚度模型，并将其纳入比奥模型；由此得到的模型称为BIMGS模型。通过使用该模型，从理论上证明了骨架体积模量与频率有关[木村正，“多孔粒状海洋沉积物的骨架体积模量”，《美国声学学会杂志》120，699 - 710（2006年）]。在本研究中，对改进的间隙刚度模型进行了重新研究，并推导了低频和高频范围的近似表达式。特别地，对BIMGS模型进行了实验验证。首先，对于玻璃珠和海滩砂，通过实验获得了高频下改进间隙刚度随粒径的变化关系。其次，利用两种酒精 - 水混合液体中玻璃珠纵向波速的测量值，验证了骨架体积模量是流体体积模量的线性函数，且骨架体积模量与频率有关，这可由BIMGS模型推导得出。最后，对于BIMGS模型的应用，结果表明，使用具有恒定骨架体积模量的比奥 - 斯托尔模型无法解释的报道中的速度频散和衰减频率依赖性，均可得到解释。
