基于不同半径分段组合的微动探测方法研究

空间自相关法是一种传统的微动勘查方法。笔者在双重圆形观测台阵中不同半径组合方式下,利用空间自相关法分别求出自相关系数以及频散曲线,对比不同半径的频散曲线,结合前人研究成果,总结出大半径组合方式在低频部分的可靠性更高,小半径组合方式在高频部分的可靠性更高,进而提出了分频段拟合贝塞尔函数、分半径平均频散曲线的方法,一定程度上扩宽了可用频率范围,提高了探测精度。通过场地实验证实了方法的有效性。

Research on microtremor survey method based on segmentation combination of different radii

The spatial autocorrelation method is a traditional microtremor survey method.The autocorrelation coefficients and the dispersion curves are obtained by the spatial autocorrelation method in different radii combinations with double circular observation array.The authors compare the dispersion curves of different radii,and then combine some previous research results to summarize the characteristics.The large radius combination method has higher reliability in the low frequency part,whereas the small radius combination method has higher reliability in the high frequency part.Therefore,the authors use the methods of sub-band fitting Bessel function and fractional average dispersion curve into different frequency bands to widen the available frequency range and improve the detection accuracy.Finally,the effectiveness of the method is verified through field experiments.