黄河粉砂沉积层低频声吸收衰减测量

一、引 言 关于沉积物中声吸收衰减与频率关系Hamilton在综合和分析了大量实验数据后认为:淤泥、粘土或泥从几赫到兆赫,砂从1千赫到兆赫、泥砂混合物从150赫到兆赫的频率范围内衰减系数随频率线性增加。Hamilton的推断是把不同地区的不同沉积层结构和不同频率范围的大量实验数据进行平滑的结果。而不同频率范围引起吸收衰减的机理不同,不同的机理应有不同的频率依赖关系。在他收集的资料中砂的(2kHz以下)低频衰减数据尤为缺少。Stoll     

MEASUREMENTS OF ACOUSTIC ABSORPTION ATTENUATION FOR FREQUENCY RANGE OF 0.2-2 kHz IN SANDY SEDIMENTS OF YELLOW RIVER(HUANGHE)

The measurements of the sound attenuation in sandy sediment of Yellow River(Huanghe)have been made in situ by explosive sources.The attenuation coefficients are determined for thefreqency range of 0.2-2kHz.The experimental results show that the attenuation coefficient α(dB/m)increases approximately as the square of frequency for the frequency range of 0.2-2kHz.Theexperimental results is in agreement with the theoretical results.In addition the sound velocity,density,porosity and grain size distribution of the sediment are given in this paper.