基于地球物理探测数据反演海底工程地质参数研究进展与展望

Research Progress and Prospect of Seabed Engineering Geological Parameters Inversion Based on Geophysical Exploration Data

海底浅部沉积物的粒度、孔隙度、密度、抗剪强度等工程地质参数是海洋沉积声学研究和海洋工程开发所需了解的基础信息,而目前对于这些物理力学参数的获取主要基于有限的海底取样或原位测试方法。声学地球物理探测是基于声学信号在沉积物中的传播得到水深地形及沉积地层结构等信息,其中一些声学参数,如海底反射系数、波阻抗、后向散射强度等与粒度、孔隙度、密度等海底工程地质参数密切相关。因此,基于声学地球物理探测数据,并结合一定数量的传统海底底质取样测试数据开展海底工程地质参数反演,具有工作效率高且获取的资料连续、信息丰富等优势,是传统海底底质取样和工程地质特性研究的有益补充。本文在论述了海底沉积物类型、物理力学参数及其声学特性的基础上,对比分析了多波束、浅地层剖面及多道地震等海底声学地球物理探测数据在海底底质物理参数反演中的优势与不足,对基于声学地球物理探测数据反演海底工程地质参数的发展前景予以分析和展望。

Engineering geological properties of shallow seabed sediment including mean grain size,porosity,density and shear strength are basic information for marine sedimentology research and marine engineering development.The acquisition of these physical and mechanical parameters is mainly based on limited seafloor sampling or in situ testing.Acoustic geophysical detection is based on the propagation of acoustic signals in sediments to obtain data on water depth topography and sedimentary stratigraphic structure,and some of the acoustic parameters such as seabed reflection coefficient,wave impedance,backscattering intensity are closely related to seafloor engineering geological parameters.The geophysical exploration data,combined with a certain amount of traditional sediment sampling data,can be used to carry out the inversion of seabed engineering geological parameters,which has the advantages of high work efficiency and continuous and abundant data collection.So it is a useful supplement to traditional seabed sediment sampling and engineering geological characteristics research.This study discussed the types of seafloor sediments,physical and mechanical parameters and their acoustic properties,compared analysis advantages and disadvantages of multi-beam,sub-bottom profiles and multi-channel seismic data in the inversion of physical and mechanical parameters of the seafloor,and proposed the development prospects of inversion of seafloor engineering geological parameters from geophysical exploration data.