复杂地形条件下面波探查技术研究与应用

发布时间：2018-06-13 18:41

本文选题：复杂地形 + 瑞雷波　；参考：《安徽理工大学》2017年硕士论文

【摘要】：多道瞬态面波法是近年来发展较快的一种新型近地表地震勘探方法,可以有效利用于多目标、多尺度的浅地表工程勘察应用中。瑞雷波勘探理论是基于水平界面半无限空间的理想假设条件下,但实际勘探工区地形往往比较复杂。因此,对复杂地形条件对多道瞬态瑞雷波勘探的影响以及复杂地形条件下的瑞雷面波最优排列参数研究,是十分有意义的。论文基于多道瞬态瑞雷面波法为技术手段,构建几种典型的复杂地形地质结构模型进行有限差分数值模拟,比较频率-速度域频散谱,研究复杂地形条件对多道瑞雷面波法勘探的影响。本文首先介绍了瑞雷波基础理论以及频散特性以及弹性波场有限差分模拟理论,利用构建单层、双层两类复杂地形模型模拟半无限空间条件,采用雷克子波为震源、完全吸收边界条件,针对地形影响、最优排列参数、震源激发位置等研究因素进行瑞雷波场正演模拟。使用频率波数法对瑞雷面波数据进行频散运算。通过对比单炮记录、波场快照、频率速度域频散谱等模拟实验结果,总结复杂地形条件对频散特征的影响和复杂地形条件下最佳排列参数选择问题。试验结果表明:凸起地形比凹陷地形对高阶频散影响小;大道间距、长排列获得的面波数据,频谱能量更加收敛;大道间距有利于提高频率速度域各阶波的分辨能力。最后通过根据两组复杂地形现场勘探试验,与高密度电阻率法进行综合对比。对比发现,与高密度电阻率法结果吻合度较高,复杂地形下面波勘探技术具有可行性。论文同时指出复杂地形条件下面波探查技术的不足以及以后的研究方向,特别是以后应该加强对复杂地形条件下瑞雷波三维有限差分模拟和时间域全波形反演的相关研究。本文研究内容成果为复杂地形条件下多道瞬态面波法应用可能遇到的问题提供理论指导。
[Abstract]:Multi-channel transient surface wave method is a new method of near-surface seismic exploration which has been developed rapidly in recent years. It can be effectively used in the application of multi-target and multi-scale shallow surface engineering survey. Rayleigh wave exploration theory is based on the ideal assumption of semi-infinite space of horizontal interface, but the topography of practical exploration area is often more complicated. Therefore, it is of great significance to study the influence of complex terrain conditions on the exploration of multi-channel transient Rayleigh waves and the optimal arrangement parameters of Rayleigh waves under complex terrain conditions. Based on the multi-channel transient Rayleigh surface wave method, several typical complex topographic and geological structure models are constructed for finite difference numerical simulation, and the frequency-velocity domain dispersion spectra are compared. The influence of complex terrain conditions on multichannel Rayleigh surface wave exploration is studied. In this paper, the basic theory of Rayleigh wave, dispersion characteristic and finite difference simulation theory of elastic wave field are introduced. The semi-infinite space condition is simulated by constructing two kinds of complex terrain models, one is single layer and the other is double layer, and the Rayleigh wavelet is used as the source of the earthquake. The forward modeling of Rayleigh wave field is carried out according to the influence of topography, the optimal alignment parameters and the excitation location of the seismic source. Frequency wavenumber method is used to calculate Rayleigh surface wave data. By comparing the simulation results of single shot record, wave field snapshot, frequency and velocity domain dispersion spectrum, the effects of complex terrain conditions on dispersion characteristics and the selection of optimal arrangement parameters under complex terrain conditions are summarized. The experimental results show that the uplift terrain has less influence on the higher order dispersion than the concave terrain, the spectral energy of the surface wave data obtained from the distance and length arrangement of the road is more convergent, and the road spacing is conducive to the improvement of the resolution ability of each order wave in the frequency and velocity domain. Finally, based on the field exploration tests of two groups of complex terrain, a comprehensive comparison is made with the high density resistivity method. It is found that there is a good agreement with the results of high density resistivity method, and the technique of wave exploration under complex terrain is feasible. At the same time, the paper points out the shortage of surface wave exploration technology under complex terrain and the future research direction, especially the research on Rayleigh wave 3D finite difference simulation and time domain full waveform inversion should be strengthened in the future. The results of this paper provide theoretical guidance for the application of multi-channel transient surface wave method in complex terrain.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P631.4

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