【摘要】 本文基于Biot理论,考虑了多孔介质中固体骨架的松弛特征,引入了纵波品质因子、横波品质因子与耗散品质因子三参数来描述黏弹双相介质波动方程.采用虚谱法在地震频段进行了波场模拟,模拟结果表明:松弛骨架机制不仅适用于高频段,也可用于解释地震频段下的弹性波衰减现象,以描述固体微细颗粒的中观松弛特征.结合小生境遗传算法对三层模型24个介质参数进行了反演,反演结果表明:无噪波场的反演结果具有较高精度,对于含噪波场,取值在奇异点附近的介质参数反演精度降低.最后,对中国东部某地区的实际资料进行了浅层参数的反演,得到了该地区的表层固体体积模量、固体密度以及品质因子.更多还原

【Abstract】 Based on the Biot theory,the relaxation effect of the solid skeleton is considered in porous media.We introduce the three parameters of P wave quality factor,S wave quality factor and diffusion quality factor to describe the poroviscoelastic wave equations.A pseudo-spectral method is used in wavefield forward modeling.Simulation results show that the skeleton-relaxed model not only works for the fluid saturated porous media in ultrasonic band.It can also be used for the explanation of elastic waves’ high attenuation in seismic band,to approximate the solid particles’ relaxation effect in a mesoscopic scale.Niche Genetic Algorithms are introduced in the inversion of 24 parameters for a three-layer model.Inversion results of the wavefield without noise hold high precision.But if white noise is added,the parameters whose true values are near singularity will get increased error.Finally,actual shot gather sections from some district in east China are processed.The solid bulk modulus,the solid density and the quality factors of the shallow layers are estimated.更多还原