海洋学研究 ›› 2023, Vol. 41 ›› Issue (4): 57-69.DOI: 10.3969/j.issn.1001-909X.2023.04.006

• 研究论文 • 上一篇    下一篇

海底不均匀沉积层斜向声学原位纵波测量的仿真研究

王莹1(), 陶春辉1,2,*(), 张国堙2, 周建平2,3, 沈洪垒4   

  1. 1.上海交通大学 海洋学院,上海 200030
    2.自然资源部海底科学重点实验室,自然资源部第二海洋研究所,浙江 杭州 310012
    3.自然资源部海洋智能观测技术创新中心,浙江 杭州 310012
    4.中国矿业大学 深地工程智能建造与健康运维全国重点实验室,江苏 徐州 221116
  • 收稿日期:2023-02-14 修回日期:2023-03-25 出版日期:2023-12-15 发布日期:2024-01-30
  • 通讯作者: 陶春辉(1968—),男,研究员,主要从事深海多金属硫化物方面的研究,E-mail:taochunhui@sio.org.cn
  • 作者简介:王莹(1998—),女,山东省烟台市人,主要从事海底声学原位测量方面的研究,E-mail:wangying5787@163.com
  • 基金资助:
    浙江省重点研发计划项目(2021C03016);上海交通大学“深蓝计划”基金与自然资源部第二海洋研究所基本科研业务费专项资金(SL2020ZD205)

Simulation study on oblique in situ acoustic longitudinal wave measurement of seafloor inhomogeneous sedimentary layer

WANG Ying1(), TAO Chunhui1,2,*(), ZHANG Guoyin2, ZHOU Jianping2,3, SHEN Honglei4   

  1. 1. School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
    2. Key Laboratory of Submarine Geosciences, Second Institute of Oceanology, MNR, Hangzhou 310012, China
    3. Technology Innovation Center for intelligent Ocean Observation, MNR, Hangzhou 310012, China
    4. State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China
  • Received:2023-02-14 Revised:2023-03-25 Online:2023-12-15 Published:2024-01-30

摘要:

海底沉积层的声学特性是开展海洋声场计算与工程地质评价的基础要素,原位测量是精确获取声学特性参数的有效手段。海底沉积层的结构分层特征以及孤石等地质异常体的存在导致其垂向、横向呈现不均匀性特征,现有的声学原位测量系统难以对不均匀性特征进行探测识别,对地层不均匀性上的识别尚且缺少判别参考。对此,该文提出了一种针对海底沉积层不均匀性的斜向声学原位纵波测量方法,利用有限元法进行了百米尺度内的沉积层斜向声学原位测量仿真研究,根据东海区域工程地质勘探资料,构建了均匀型沉积层、分层型沉积层及含孤石型沉积层三种模型,基于斜向原位测量方法开展了沉积层声速测量仿真。结果表明,斜向原位测量方法对大深度沉积层中的不均匀性具有较好的识别效果,通过引入等效偏移距概念,对原有声速计算公式进行了改进,有效提高了异常识别的准确性。斜向声学原位测量方法是对现有沉积层原位测量方式的有效拓展,将有助于推动原位测量在海洋工程勘察中的进一步应用。

关键词: 海底沉积层, 斜向声学原位测量, 声学特性, 仿真

Abstract:

Acoustic characteristics of seafloor sediments are the basic elements of marine sound field calculation and engineering geological evaluation. In situ measurement is an effective means to accurately obtain acoustic characteristic parameters. The structure stratification characteristics and the existence of geological anomalies such as boulders lead to vertical and lateral heterogeneity, and the existing acoustic in situ measurement system is difficult to detect and recognize the nonuniform features, and there is a lack of discrimination reference for the identification of stratigraphic non-uniformity. In this study, an oblique acoustic in situ longitudinal wave measurement method based on the heterogeneity of seafloor deposition was proposed, and a simulation study on the oblique acoustic in situ measurement of sediments within a hundred meters was carried out by using the finite element method. According to the data of regional geological engineering exploration data in the East China Sea, three models of uniform sedimentary layer, stratified sedimentary layer, and a sedimentary layer containing the boulder were constructed, and a simulation of acoustic velocity measurement in the sedimentary layer was carried out based on oblique in situ measurement method. The results show that the oblique in situ measurement method was effective in identifying the inhomogeneity in the large-depth sedimentary layer. By introducing the concept of equivalent offset, the original acoustic velocity calculation formula was improved, effectively improving anomaly identification accuracy. The oblique acoustic in situ measurement method proposed in this study was an effective extension of the existing in situ measurement methods of sedimentary layers, which will help to promote the further application of in situ measurement in marine engineering surveys.

Key words: seafloor sedimentary layers, oblique acoustic in situ measurement, acoustic characteristic, simulation

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