應用新型地聲檢知器 Raspberry Shake 3D 於坡地災害監測之研究

We applied a new geophone, the Raspberry Shake 3D (RS3D), with a measuring frequency of 0.5–40 Hz to detect the ground vibrations produced by an artificial debris flow. Recorded signals were compared with those obtained using a conventional geophone with a measuring frequency of 5–175 Hz. The study site was located at the Landao Creek experimental station in Huisun Forest in Nantou, Taiwan. Water from the Nenggao Canal was guided into Landao Creek to induce a dam breach and generate the artificial debris flow. The test results reveal that the RS3D can detect ground vibration signals with frequencies lower than 5 Hz, which is beyond the capability of the conventional geophone tested. Furthermore, during the field test, the RS3D detected ground tremors from occasional local earthquake. This further demonstrates the capability of the RS3D for monitoring ground vibrations in its surrounding region. Because the decay of low-frequency ground vibrations is slower than that of high-frequency ground vibrations, the RS3D can detect slope failures, such as landslides, debris flows, and rockfalls, that generate ground vibrations earlier than the conventional geophone can. This increases the duration of evacuation and response time for disaster mitigation.