相邻道瞬态瑞雷波法在工程勘察中的应用

Application of transient Rayleigh wave in engineering investigation

常规相邻道频散曲线计算方法通常采用等频率间隔的快速傅里叶变换,其低频段频点采样间隔相对过大,导致深层信息成像能力较差。为了克服以上缺点,我们对相邻道频散曲线计算方法进行了改进,通过对瑞雷波记录进行频谱分析,确定计算频散曲线的频率区间,对频率区间按对数值等分,得到一系列变频率间隔的频率点,使高频到低频频点采样间隔逐渐变小,减小低频段的频率采样间隔,提高了瞬态瑞雷波法对低频段、深层结构的成像能力。通过实际工程应用,验证了该方法的正确性和有效性。

To overcome the disadvantages of common method in calculation dispersion curves,which discrete spacing oversize at low frequency area and low contrast resolution in the depths,we improve the calculation method of dispersion curves through equal section logarithm of the frequency range,and obtained a series of number frequency at vary frequency interval.Make the discrete frequency spacing reduced from higher frequency to lower frequency and can effectively reduce the discrete frequency spacing to promote the vertical resolution and depth exploration precision of transient Rayleigh wave at lower frequency.The method is proved to be correctness and affectivity by engineering application.