104 / 2023-06-15 15:48:50

Research on the damage and dynamic support of roadway surrounding rock based on the reconstructing longitudinal and transverse waves

roadway support,Microseismic distribution pattern,Dynamic disturbance,Waveform decomposition,Surrounding rock damage

The energy level and frequency of induced seismicity increase as mining excavation goes deeper, leading to the increasingly serious damage of the roadway caused by the seismic wave. The SST-EMD method is used to decompose the real mixed seismic wave signal collected in the field into P wave and S wave, and accurately simulate the damage characteristics of roadway surrounding rock under dynamic and static load conditions. Based on this, a method of roadway anti-dynamic load support considering static load and reconstructed seismic wave disturbance is proposed. A 3D dynamic model is constructed to carry out variable parametric studies on the influence of loading method, seismic energy level and source-tunnel distance on the surrounding rock reaction of the tunnel. The velocity, displacement and yielding zone results show that theoretically orthogonal oscillating directions and damaging pattern of P and S waves are more accurate when applying SST-EMD decomposed waves than using mixed waves at the source. Under the effect of P wave and S wave oscillation, the vertical displacement at the top position of the tunnel is much higher than the horizontal displacement, while the horizontal displacement at the sidewall position is greater. Under the influence of seismic waves, the particle vibration velocity, displacement and yielding zone of surrounding rock of roadway are proportional to the energy level of seismic, but inversely proportional to the source-roadway distance. The percentage of damage due to S waves increases with increasing energy level, from 75.8% to 85.8%, and increases then decreases with increasing source-tunnel wall distance. Eventually, a roadway dynamic support design is optimized based on the proposed methodology considering the seismic damage characteristics of roadway. The proposed methodology could guide roadway dynamic support design while preventing excessive support strength or insufficient support effect.