Seismic surface waves that were likely converted from incident body waves were used to detect a 3 m deep tunnel using two novel processing methods. In data acquired at a tunnel test site, a unique forward-propagating wave (traveling away from the tunnel and seismic source) was identified as an early-arriving surface wave converted at the tunnel from an incident body wave. To our knowledge, our research represents the first time converted surface waves have been observed originating from a tunnel. We have developed two novel processing methods targeting this unique wavefield component for detecting tunnels, cavities, or other shallow anomalies. The first is a time-domain imaging method that takes advantage of the unique kinematic characteristics of converted surface waves to produce a cross section with a coherent, high-amplitude signature originating from the horizontal location of the tunnel. The second method uses frequency-domain analysis of surface-wave amplitudes, which reveals increased amplitudes (primarily from converted surface waves) at locations expected for the tunnel. These proposed approaches for analysis of converted surface waves were successfully used to detect the tunnel and accurately interpret its horizontal location in real-world data. These novel methods could be the key for detecting shallow tunnels or other subsurface anomalies and complement existing seismic detection methods.

中文翻译：

---

使用转换后的表面波进行浅层隧道检测

地震表面波很可能是由入射体波转换而来的，它使用两种新颖的处理方法来探测3 m深的隧道。在隧道测试点获得的数据中，唯一的前向传播波（远离隧道和地震震源行进）被识别为在隧道处从入射体波转换而来的早期到达表面波。据我们所知，我们的研究代表首次观察到源自隧道的转换表面波。我们已经针对这种独特的波场分量开发了两种新颖的处理方法，用于检测隧道，空腔或其他浅层异常。第一种是时域成像方法，它利用转换后的表面波的独特运动学特性来产生具有相干，源于隧道水平位置的高振幅信号。第二种方法使用表面波振幅的频域分析，该分析揭示了在隧道预期位置处振幅的增加（主要是来自转换后的表面波）。这些建议的转换面波分析方法已成功用于检测隧道并在实际数据中准确解释其水平位置。这些新颖的方法可能是检测浅隧道或其他地下异常的关键，并可以补充现有的地震检测方法。这些建议的转换面波分析方法已成功用于检测隧道并在实际数据中准确解释其水平位置。这些新颖的方法可能是检测浅隧道或其他地下异常的关键，并可以补充现有的地震检测方法。这些建议的转换面波分析方法已成功用于检测隧道并在实际数据中准确解释其水平位置。这些新颖的方法可能是检测浅隧道或其他地下异常的关键，并可以补充现有的地震检测方法。