Effective signal reconstruction and chaotic characteristics of electro-seismic signal of granite splitting failure

Abstract

Electromagnetic radiation and vibration monitoring technologies are widely used in the monitoring and early warning of dynamic disasters in underground engineering, which is of great significance to the safe and efficient development of underground engineering. In-depth study of electro-seismic signals is helpful to promote the development of granite mass monitoring and early warning technology. However, the current analysis of electromagnetic radiation and vibration signals (electro-seismic) mainly focuses on the correlation and time-frequency characteristics of signals. There are few studies on the nonlinear dynamic characteristics of granite fracture electro-seismic signals, and the relevant characteristics are not yet clear. Based on this, this paper uses the combination of empirical mode signal (EMD) reconstruction and fractal theory to analyze the chaotic characteristics of electro-seismic signals of granite splitting failure, and reveals the nonlinear dynamic characteristics of electro-seismic signals. The results show that the electromagnetic radiation generated by granite splitting failure is in good agreement with the vibration signal in time, and the frequency spectrum of the electro-seismic signal generated by splitting failure is concentrated in the middle and low frequency band. The box dimension of the effective electromagnetic radiation signal of granite failure is DE=1.6006, and the box dimension of the effective vibration signal is DA=1.5948, and the frequency structure characteristics of the two are highly similar. The effective electromagnetic radiation and vibration signals of granite fracture can be obtained by the EMD decomposition and reconstruction method. It is more accurate to describe the chaotic characteristics of granite fracture electro-seismic signals by using the EMD decomposition and reconstruction to remove the interference of high frequency. The effective electromagnetic radiation on the vibration signal contains more low-frequency and high-energy signals than the original signal, which characterizes the propagation of small cracks. The non-uniformity of the reconstructed electro-seismic signal is significantly higher than that of the initial signal, and the frequency relationship of different energy signals decreases. The reconstructed effective electro-seismic signal is mainly low-frequency and high-energy signals, but the non-uniformity of the vibration signal is greater than that of electromagnetic radiation.

Keywords

• electromagnetic radiation-vibration signal
• signal reconstruction
• empirical mode decomposition
• chaos analysis
• fractal dimension