Experimental Study on Monitoring of Dike Piping Process Based on Acoustic Emission Technology

Acoustic emission (AE) is employed in this study to monitor piping failure process in the dike subjected to varied head action. Piping is the main reason for the seepage failure of dikes and dams, and the AE characterization of piping process is investigated. The laboratory experiments and data analyses were carried out using specially designed physical model and data acquisition systems. The monitored data were analyzed using four methods, namely, AE ringing count, fractal dimension, frequency domain analyses and b value. The analysis results showed that the piping failure process can be divided into 3 phases: seepage erosion, piping generation, and piping development. In different stage, the activity of the AE signals is related to seepage flow and seepage pressure. Based on the fractal dimension and waveform energy spectrum distribution analysis in the entire process of piping failure, the measured acoustic signals in the test can reflect both a seepage-induced and a soil-seepage induced AE. The AE ringing count fractal dimension and waveform energy spectrum can be used as new index monitoring the occurrence and development of piping. The abrupt change of AE fractal dimension and AE energy spectrums curve with time can be considered as the precursor to piping occurrence and piping development. What's more the b value of the AE signal can be used to describe the piping state.