Ground vibration analysis of leak signals from buried liquid-filled pipes: An experimental investigation

•Frequency characteristics of leakage signals for buried metal and plastic pipes.•Numerical analysis of wave propagation in the soil.•Attenuation law of leakage signal propagation in the soil and on the ground surface. The frequency and attenuation of leak signals from buried liquid-filled plastic and metal pipes were investigated by collecting ground surface vibrations under different conditions at an indoor experimental test facility. The effects of pipe pressure and material on the effective frequency content of the leak signals were investigated. The attenuation of the leak signals propagating in the soil and through the ground surface was studied by comparing numerical and experimental results. We found that the leak signals measured on the ground surface were wide-band signals and attenuate the high-frequency content more easily compared with the low-frequency content. In the vicinity of the leak source, the attenuation of the leak signal propagating in the soil is mainly attributed to the P2-wave. Our work can help improve the performance of electronic listening devices and develop novel acoustic leak detection strategies.