时—频分析在瑞雷面波相速度提取中的应用

【作者】 陈亚东；

【导师】 胡建平；

【作者基本信息】 长安大学 ， 地球探测与信息技术， 2003， 硕士

【摘要】 瑞雷面波勘探是近年来兴起的一种新的浅层地震勘探方法，广泛应用于工程勘探、岩土工程以及地基评估等方面。其主要思想是利用瑞雷波的频散特性来反映浅层地质问题。根据激振方式的不同，瑞雷面波勘探分为稳态法和瞬态法两种。目前，多采用瞬态法。 在对瑞雷面波勘探资料进行处理时，以往主要采用常规的Fourier变换。但由于Fourier变换是整体变换，不能反映信号的时频局域特性，而我们最需要的就是这些局部特性。因此，我们采用时-频分析方法对资料进行处理。时-频分析方法的一个最大优点就是能同时反映时域和频域的变化情况。本文首先分析了瑞雷波的频散特性，并介绍了瑞雷面波勘探的两种方法。在对资料进行处理时，文中分别采用了传统Fourier变换和时-频分析两种方法。其次，通过对理论模型试算，对两种方法的处理结果进行了比较，证明程序设计是合理的，所采用的时-频分析方法是可行的、适用的、稳定的。通过对大量的实际资料进行处理，取得了比较明显的效果，更进一步说明了时-频分析方法的准确性和实用性，并具有较好的应用效果和发展前景。更多还原

【Abstract】 Rayleigh wave exploration is a new seismic exploration method for low layer in these years rised. The method applies to many aspects widely, such as engineering prospecting, rock-soil engineering, evaluating groundsill. It’s main idea that making use of frequency dispersion of Rayleigh wave to reveal geology structure of low layer. Rayleigh wave exploration is divided into steady state way and transient state way according to the differ of explode mode. At present, people adopt transient method mostly.People mostly choose traditional Fourier transform to process surface wave data anciently. Traditional Fourier transform is whole transform and can’t reflect signal’s local characteristic that is our needing. In this paper, we adopt time-frequency analysis method to process data, this method has a advantage that it can reflect the changing of time and frequency at mean time. Moreover, we analyze the frequency dispersion of Rayleigh wave firstly, then we introduce the two methods of surface wave exploration. We adopt traditional Fourier transform and time-frequency analysis to process data respectively. Afterwards we testify that the program is reasonable and time-frequency analysis method is feasible, in point and reliable through calculating surface wave exploration theoretical model and comparing the processing result of the two methods. Finally we obtain obvious effect by the processing of many practical data, and further demonstrate the accuracy and the practicability of the time-frequency analysis, and the method has the better apply effect and development foreground.更多还原