基于谱减法的隧道地震波超前探测去噪方法

Denoising Method Based on Spectral Subtraction for Seismic Wave Advance Detection in Tunnels

为快速有效地去除隧道地震超前探测数据中具有随机、频带广和能量强特征的噪声,提升偏移成像质量,进而有效探明隧道掌子面前方灾害源,充分利用谱减法在压制随机噪声上的优势,将其引入隧道地震波探测数据处理中,形成基于谱减法的隧道地震波超前探测去噪方法。该去噪方法可以有效去除随机噪声且计算效率较高,可以满足隧道的快速施工要求。通过对典型不良地质模型进行数值模拟,表明利用谱减法可有效压制隧道环境中的随机噪声干扰,地震记录中反射波信号信噪比更高,在此基础上的偏移成像结果伪像干扰更少,可有效提升探测准确性。将该方法应用至实际隧道地震探测中,成功探明了隧道掌子面前方的岩体破碎带分布位置和范围,证明应用该方法进行超前探测具有有效性和实用性。

Migration imaging quality can be improved and the disaster source ahead of the tunnel face can be detected efficiently by quickly and effectively removing the noise associated with random broadband and intense energy characteristics from tunnel advance seismic wave detection data.In this study,a denoising method for tunnel advance seismic wave detection is established by introducing the advantages of the spectral subtraction method in suppressing random noise into tunnel seismic wave detection data processing.The denoising method can effectively remove random noise and has high computational efficiency that meets the fast construction requirements of the tunnel.An numerical simulation analysis of typical adverse geological models shows that spectral subtraction can effectively suppress the random noise interference in the tunnel environment,increase the signal-to-noise ratio of reflected wave signals in the seismic record,and reduce the artifactual interference in the offset imaging results,effectively improving the detection accuracy.Accordingly,the method was applied to a case project,and the location and extent of the rock fracture zone in front of the tunnel face were successfully detected,proving the effectiveness and practicality of the method for future applications.