Dynamic response characteristics of coal and rock with different stress states under seismic wave action

The study investigates the stress, energy and deformation response characteristics of the surrounding rock under different stress condition with superimposed dynamic and static loads. It found that with the increase of mountain height, high energy microseismic events begin to rise gradually. The number of microseismic events exhibit initial increase followed by a decrease, reaching a peak in the region where the stress change rate (Cr) is at its highest. The irreversible deformation and stress release of surrounding rock mainly occurred in the mixed loading stage of P- and S-waves. After the excitation of seismic wave, two sides of surrounding rock with a wide range of stress concentration zone experienced significant stress drop. With the increase of stress under same Cr, the degree of the peak particle velocity (PPV) and energy accumulation in the surrounding rock gradually rises, the amount of stress drop and deformation gradually decreases, while the degree of decompression gradually reduces. Under the same stress condition, the surrounding rock in high Cr region has response characteristics of small PPV and deformation, minimal stress drop and weak energy distribution. The distribution of stress, energy and displacement was asymmetrical, aligning with the observed characteristics of the on-site rockburst manifestation.