多道瞬态面波法在高铁岩溶检测中的应用

Application of Multichannel Transient Surface Wave Method in Karst Detection of High-speed Railway

结合实际地层情况,采用有限差分法对水平三层均质地质模型和含溶洞地质模型进行了正演模拟,对正演数据进行了F-K频散计算,综合对面波单炮记录与频散谱进行了分析,说明溶洞的存在对频散特征的影响较大。以贵广高铁某段的岩溶检测例,对得到的地震数据进行频散分析,并进行处理得到二维的速度剖面,结合以往地质资料分析了区域内的岩溶发育情况。数值模拟与应用实例表明:多道瞬态面波法对高铁岩溶检测具有良好效果。

In combination with the actual stratigraphic conditions,the forward three-dimensional homogeneous geological model and the geological model containing karst caves are simulated by the finite difference method. The F-K dispersion calculation is performed on the forward data,and the integrated single-shot recording and dispersion of the surface wave is performed. Spectrum analysis shows that the presence of caverns has a greater impact on dispersion characteristics. Using the karst detection example of a section of Nanguang High-speed Railway,the seismic data obtained were subjected to frequency dispersion analysis and processed to obtain a two-dimensional velocity profile,which combined with previous geological data to analyze the karst development in the region. Numerical simulation and application examples show that multi-channel transient surface wave method has good effect on high-speed railway karst detection.