基于波场分离的高频面波波形反演研究

发布时间：2022-02-12 11:21

　　城镇化是人类社会现代化发展的必然趋势。在未来的10年里,中国城镇化进程将以其历史上最高的速度运行。中国城镇化对地下空间的需求极大。如能在我国现阶段城镇化发展对环境的影响和破坏尚未达到无法控制之前,深入研究和利用高频面波方法,有效探测、检测和监测与人类生存息息相关的浅地表环境,为城镇发展提供科学观测数据,无疑对促进我国社会的高速可持续发展至关重要。浅地表地球物理方法在合理开发、综合利用和有效保护地下空间的应用中面临诸多理论和实际问题。随着浅层勘探方法的不断发展,如何提高地震反演的精度,精确的刻画浅地表地下结构已成为浅层勘探亟待解决的问题。瑞雷波和勒夫波多道分析方法（MASW和MALW）均是基于频散曲线的反演获得地下S波速度结构。由于频散曲线正演基于水平层状模型假设,瑞雷波和勒夫波多道分析方法均仅适用于水平层状模型及横向S波速度缓变的地球模型。这被视为目前高频面波方法发展的一个重要局限。另一个问题是频散曲线模式的正确识别,如泄漏波和“模式接吻”的存在,实际资料处理中,如没有其它资料对模型的限制,频散曲线模式的正确识别几乎是不可能的。对于含有软夹层、起伏地表等较为复杂的地球模型,频散曲线的提... 

【文章来源】：中国地质大学湖北省211工程院校教育部直属院校

【文章页数】：124 页

【学位级别】：博士

【文章目录】：
作者简历
中文摘要
Abstract
Chapter 1 Introduction
    1.1 Surface-wave methods
    1.2 Surface-waves challenges
    1.3 Thesis Objective
    1.4 Thesis Structure
Chapter 2 The Theory of Full Waveform Inversion
    2.1 The forward problem
        2.1.1 The elastic wave equations
        2.1.2 Initial and Boundary Conditions
        2.1.3 The horizontal free surface
    2.2 The adjoint problem
        2.2.1 The optimum model
        2.2.2 The adjoint state method
        2.2.3 Multiscale strategy
Chapter 3 The Cross-talk Influences Between Different Parameters
    3.1 The gradients of different parameters
    3.2 The Circle-Triangle-Square model
        3.2.1 True and initial models
        3.2.2 Acquisition geometry and forward modelling
        3.2.3 FWI setup
        3.2.4 Results
        3.2.5 Comparisons
    3.3 The Influence of the initial P-wave velocity and density
        3.3.1 True P-wave velocity and true density model
        3.3.2 Inaccurate P-wave velocity and inaccurate density model
        3.3.3 Inaccurate P-wave velocity and true density model
        3.3.4 True P-wave velocity and inaccurate density model
        3.3.5 Summary
Chapter 4 The Seismic Wavefield Separation method
    4.1 The separation of Surface and Body Wave based on High-resolution Radon Transform
        4.1.1 Method
        4.1.2 Examples
    4.2 A pitfall of muting and removing bad traces in dispersion analysis
        4.2.1 Synthetic test
        4.2.2 Real-world example
    4.3 Conclusions
Chapter 5 Feasibility of P-wave Velocity Building by Acoustic Full-waveform Inversion Based on Wavefield Separation
    5.1 Workflow
    5.2 Fault model
Chapter 6 The Resolution Analysis in Elastic Full-waveform Inversion
    6.1 The receiver spread lengths
    6.2 The number of the receivers
    6.3 The number of the sources
    6.4 The dominant frequency of the wavelet
Chapter 7 Conclusions
致谢
References


【参考文献】：
期刊论文
[1]High-Frequency Rayleigh-Wave Method[J]. Richard D Miller,徐义贤,罗银河,陈超,刘江平,Julian Ivanov.  Journal of Earth Science. 2009(03)



本文编号：3621626