海底沉积物压缩波速度与切变波速度的关系

基于连续介质假设,根据无吸收各向同性弹性介质通用方程分析沉积物声波传播关系,提出应用弹性结构分布因子表达的声速通用模型(GMSS,General Model of Sound Speed)分析海底沉积物的声速特性;通过研究Willey时间平均模型、Wood方程、Gassmann方程、Buckingham模型、Biot-Stoll模型和EDFM模型,可以表述成GMSS通用模型中的弹性结构分布因子的具体表达形式,得出GMSS通用模型在解释压缩波速度和切变波速度特性上具有一致性的特点。GMSS通用模型具有弹性结构分布因子、孔隙度、孔隙海水的等效密度和等效弹性模量、固相颗粒的等效密度、固相颗粒的等效体积弹性模量和等效切变弹性模量共7个参数,为研究海底沉积物压缩波和切变波速度提供了一种模型简单、参数少、通用性强的方法。但也需要从物理结构上以及应力应变关系上开展更为深入的分析和探寻GMSS模型的物理意义和参数测量的方法。 

Relationship of sound speeds between compressional wave and shear wave of seafloor sediments

Based on the assumption of continuous medium, a general model of sound speed (GMSS) is put forward to analyze acoustic characteristics of seafloor sediments by introducing the elastic structure factor, with the analysis of acoustic wave propagation in sediment by using the general equation of non-absorbing isotropic elastic medium. With the study of comparison of Willey time average model, Wood equation, Gassmann equation, Buckingham model, Biot-Stoll model and EDFM model with the GMSS, they can be expressed with GMSS in some specific elastic structure factor status. And GMSS model has the consistency in the interpretation of compressional wave velocity and shear wave velocity characteristics. GMSS is with seven parameters included elastic structure distribution factor, porosity, equivalent densities and equivalent elastic modules of pore water and solid particles, and equivalent shear modules of solid particles. It provides a simple and universal method with few parameters for the study of seafloor sediment compressional wave and shear wave velocity. Moreover, there still need to carry out a more in-depth analysis to explore the physical meaning and parameter measurement of the model of GMSS considering the physical structure and the stress-strain relationship.