Experimental study of Rockburst in structurally controlled deep-buried roadways under static–dynamic coupling via true triaxial tests

Abstract

This study explores the influence of different lateral pressure coefficients on rockbursts in deep-buried structural roadways under dynamic disturbance, using true triaxial experiments combined with acoustic emission and SEM analysis. The test results show that the lateral pressure coefficient significantly influences both the scale and location of roadway damage on the structural surface. The failure mode of the implied structural test samples is mainly the crack failure of the weak laminate, while the spalling of the edge of the structural plane is mainly the exposed structural surface. The initial damage of the implicit structural plane is the crack propagation of the weak layer, while the exposed structural plane begins with the separation of the free end of the structural plane. The structural planes significantly weaken specimen strength and accelerate overall failure. Based on fracture modes, two types of structural rockbursts are identified: surface-pressure-induced and buckling-induced. As the lateral pressure coefficient decreases, the cumulative AE count, energy release, and fractal dimension of rockburst debris exhibit a “V-shaped” trend initially weakening, then intensifying. Meanwhile, microcrack numbers decline and the proportion of shear cracks increases. Rockbursts in implied structures are more intense than in exposed ones. Although higher lateral pressure coefficients stabilize initial rock conditions, ultimately lead to stronger rockbursts. Both specimen types exhibit highly “instantaneous” and “sudden” failure, reflected by sharp peaks in acoustic emission activity.