Research on vibration effect of tunnel blasting based on an improved Hilbert–Huang transform

Through a tunnel-blasting project, the effect of tunnel-blasting vibration has been analyzed from the perspective of vibration energy transfer. The non-linear regression method was used to obtain the prediction equation for blast vibration velocity based on the field blast vibration data. Then, the maximum charge per delay of the blasting construction of the tunnel was obtained through the formula inversion. Based on the traditional Hilbert transform, a novel Hilbert–Huang transform (HHT) analysis method considering Complete Ensemble Empirical Mode Decomposition with Adaptive Noise decomposition (CEEMDAN) and wavelet packet threshold de-noising method has been proposed, the feasibility of which was verified using the field blast vibration signals. It has been proved that the improved HHT analysis method can be used to analyze the influence of the different blasting vibration parameters on the regular distribution of vibration energy. In addition, the dimensional analysis method was used to establish the blasting vibration energy prediction model. The results of this research show that the improved HHT analysis method can solve the problem of modal aliasing caused by the traditional decomposition method, and can obtain the purified main modal components, which improves the adaptability of HHT analysis. In addition, with the increase of the distance between blast area and the maximum charge per delay, the high-frequency energy of the blasting signal gradually weakens, while the dominant energy frequency band diverts to the low-frequency band. The methods and conclusions of this research can provide a certain reference for the controlled blasting construction in similar cases.