Mechanistic coupling of cutterhead vibrations and wave propagation in deep coal-mine TBM excavation

Tunnel-boring machine (TBM) excavation in deep coal-mine roadways is increasingly constrained by cutter-induced vibrations that accelerate tool wear and can destabilize the surrounding rock mass; yet, the mechanistic pathway linking vibration generation, wave-field propagation, and rock-mass response remains unresolved. To bridge this gap, the present study couples high-resolution transient stress-wave detection acquired in an operating coal-mine TBM with a three-dimensional discrete-element “spin–orbit” cutter model that explicitly represents self-rotation, planetary motion, and jointed coal-measure heterogeneity. The integrated framework captures full-bandwidth, three-component vibration signatures at the cutterhead and inside the rock, and tracks their spatial–temporal evolution. Field data reveal that rock-breaking vibration amplitudes are approximately 50-fold those recorded during shutdown and twofold to fourfold those during idle rotation, exhibiting persistent, quasi-periodic patterns. Dominant frequency bands concentrate at 30–90 Hz along the heading direction, 60–90 Hz horizontally, and 20–40 Hz as well as 60–80 Hz vertically. Numerical simulations show that normal forces constitute the largest cyclic load, followed by rolling forces, whereas lateral forces remain minor without a pronounced spectral peak. Stress-wave analyses indicate that lateral attenuation within jointed strata proceeds markedly faster than longitudinal decay, and that longitudinal amplitudes diminish more rapidly outside the cutter-path circle than inside. By quantitatively linking cutter-level loading fluctuations to directional wave attenuation, this study furnishes threshold indices for cutter optimization, tunneling-parameter tuning, and real-time rock-mass hazard monitoring. The proposed methodology advances machine–rock coupling theory and provides a practical foundation for vibration-informed support design and safer, more cost-effective coal-mine TBM excavation.