Research on vibration response characteristics of circumferential water coupling blasting seismic exploration technology in loess layer areas

To solve the problem of low signal-to-noise ratio and accuracy of seismic data obtained from traditional explosive sources in special terrains such as loess, field experiments were conducted using the circular water-coupled blasting method to artificially induce earthquakes. By monitoring the ground vibration response using blast seismographs, the variation of particle vibration velocity with distance from the explosion center was analyzed, and the time-frequency-energy characteristics of the velocity vibration signal were studied using the Hilbert-Huang transform. Seismic results for circular water-coupled blasting were obtained using detectors, and the reliability of the seismic data was evaluated by assessing the continuity of the target layer via hyperbolic time windows and considering indicators such as energy and signal-to-noise ratio. The research results showed that the peak particle velocity at the ground surface was higher with the Circular water coupled blasting method, with an average peak particle velocity of 3.304 cm/s compared to 2.29 cm/s with traditional blasting, representing a 44.3% increase. The decay rate of the peak velocity with increasing distance from the explosion center was slower, which helped alleviate energy loss and dissipation of seismic waves in loess regions. The correlation and frequency band energy of each intrinsic mode function component obtained through empirical mode decomposition (EMD) exhibited a normal distribution, with lower first and last modes and higher intermediate modes. The instantaneous energy peak of the vibration signal with traditional blasting reached 3.13 (cm/s)2·Hz, while it was 13.56 (cm/s)2·Hz with Circular water coupled blasting, indicating a significantly higher energy level with the latter method. The three indicators, main frequency, energy, and signal-to-noise ratio, within the hyperbolic time window range of Circular water coupled blasting were all higher than those of traditional blasting, with improvements of 55.9%, 33.3%, and 12.11%, respectively. Thus, seismic data obtained under water-coupled blasting conditions had higher quality. Circular water coupled blasting exhibited larger peak particle velocity, slower decay, and better continuity of seismic data within the hyperbolic target layer.