基于探地雷达单道信号处理的岩溶分析方法

探地雷达（GPR）作为岩溶隧道超前地质预报的主要手段广泛运用于隧道岩溶探测，但GPR自带分析软件所得时间剖面图只能进行岩溶定性分析，无法较准确地确定岩溶的位置、大小和形状。基于此，提出一种基于GPR原始数据的单道信号计算岩溶位置和大小的方法。具体做法主要包括：先用地质雷达自带分析软件确定岩溶位于哪几道信号上，再将这几道信号的数据利用自编程序提取并作Hilbert函数变换，绘出信号的瞬时振幅、相位和频率图（三瞬图），根据每道三瞬图图像突变的位置确定岩溶的起、终点，最后联合各道计算结果确定岩溶的位置、大小和形状。上述方法在赣龙铁路中复隧道DK189+135、DK189+75断面岩溶探测中得到了成功运用。实践证明，该方法能较准确地确定岩溶的位置、大小和形状，是基于探地雷达探测岩溶分析的可行方法。

Analysis method of karst based on single channel signal processing by ground penetrating radar

Ground penetrating radar (GPR) has been widely used in tunnel karst detection as a main tunnel advance geological forecast mean. But its time profile obtained by the analysis software in GPR can only analyze karst qualitatively, and is difficult to determine the size, location, shape of karst cave. In this context, a single channel signal method is developed for calculating karst position and the size based on GPR data. First, analysis software in GPR are used to determine which signal channel a karst is located in, then the data of signal with regard to the karst is extracted by self-compiled program and is transformed using the Hilbert function so as to draw out the figure of instantaneous amplitude, instantaneous phase, instantaneous frequency of signal (denoted as three instantaneous figure). and then mutation point of "three instantaneous figure" of each signal is integrated to determine the starting point and the end point of a karst. At last, the caculated results of all channel signals are united to determine the karst position, size and shape. The proposed method is applied to judge the position, size and shape of the karst at the section of DK189 + 135, DK189 + 75 in Zhongfu tunnel of Gan-Long railway, which proved that the method is applicable.