CAJ | 학술논문

航行舰船在海底岩土层中引起的弹性波被称为舰船地震波,主要由舰船低频辐射噪声引起,可用于识别舰船目标.将舰船地震波简化为液固多层半无限空间低频点声源引起的地震波动问题,基于波数积分方法,通过FFP数值积分得到了海底表面声压、位移和加速度的频率特性曲线,分析了不同浅海环境对点声源海底地震波的波动特征的影响.结果表明:软质海底竖直方向加速度具有明显的低频通过特征,点声源海底地震波频域特征具有方向性;接收横距、岩土层吸收衰减系数和软硬程度、水深、沉积层厚度等均对点声源海底地震波的波动特征具有影响.
항행함선재해저암토층중인기적탄성파피칭위함선지진파,주요유함선저빈복사조성인기,가용우식별함선목표.장함선지진파간화위액고다층반무한공간저빈점성원인기적지진파동문제,기우파수적분방법,통과FFP수치적분득도료해저표면성압、위이화가속도적빈솔특성곡선,분석료불동천해배경대점성원해저지진파적파동특정적영향.결과표명:연질해저수직방향가속도구유명현적저빈통과특정,점성원해저지진파빈역특정구유방향성;접수횡거、암토층흡수쇠감계수화연경정도、수심、침적층후도등균대점성원해저지진파적파동특정구유영향.
The elastic wave in seabed caused by the low frequency noise of sailing vessel is the so-called ship caused seismic wave that can be used to identify ship target. The ship caused seismic wave is simplified to the seismic wave generated by a low frequency point sound source in a liquid-solid multi-layered semi-space in this paper. Based on the wave-number integration technique, the characteristic curves of acoustic pressure, displacement and acceleration on the surface of seabed varied with frequency are obtained by FFP numerical evaluation technique. The influences of various shallow water circumstances on the characteristics of the seismic wave in seabed are discussed. According to the calculation results, the characteristic of the vertical acceleration in soft seabed is dominant in low frequency band and differs from the horizontal acceleration. The characteristics of the seismic wave in seabed are apparently influenced by receiver distance, attenuation and stiffness of sediment, water depth and sediment thickness.