中文摘要：

气泡对海底沉积物的声学物理特性的影响在海洋学、海洋地质学和海洋地球物理学等领域中都有着重要的研究意义.利用Micro-CT扫描仪对沉积物样品进行无损检测扫描,根据沉积物样品中水、气和固体颗粒对X射线吸收率的不同,提取了沉积物的气体体积（气泡）含量.利用智能非金属超声检测仪对沉积物样品进行超声无损测定,得到沉积物声速与衰减.通过回归分析,建立了样品采集海域沉积物孔隙填充气体与流体含量与沉积物声学特性之间的相关关系.结果表明：含气量的少许增大就会引起声速的急剧降低和声衰减的急剧上升,但含气量超过10%后,这种上升和降低的幅度明显减小.

英文摘要：

The effect of gas bubble on acoustic characteristic of sediment is important for ocean science, ocean geology, ocean geophysics, etc. Twenty five samples of ocean bottom sediments are extracted through gravity sampling equipment from the East China Sea and are sealed in PVC pipes for storage in order to study the effect of gas bubble on acoustic characteristic of sediment. In order to obtain the gas content of sediment, in this the paper the Micro-CT scanning technology is introduced into sediment measuring method. The different X ray absorption rates of water, gas and solid particles in sediment samples are obtained through Micro-CT scanning using Siemens＇ Micro-CT scanner. The gas volume content and water volume content in sediment can be obtained according to CT number distribution. The acoustic measurement is carried out in laboratory using intelligent nonmetal ultrasonic detector and the 40 kHz waves are launched from one side of the sediment sample and obtained from another side. The acoustic attenuation can be obtained according to the amplitudes of launched and received waves and the acoustic velocity can be obtained according to travelling time when acoustic wave goes through the sediment. The attenuation of sediment sample is about a few to twenty and the velocity is about 1100 to 1700 m·s-1. By mean of analysis of regression, the correlations are obtained among gas content, fluid content, acoustic velocity, attenuation and power function, which better match the measuring data. The result of study indicates that slight augment of gas content can cause sharp decrease of acoustic velocity and rapid increase of acoustic attenuation. The increment and decrement decrease obviously when the gas content exceeds 10%. The result in this paper is useful to explore oil and gas seismic.