Rockburst failure characteristics and energy evolution law of cross-layer anchored rock mass based on optical-thermal-acoustic combinative monitoring

• Anchoring suppresses transverse deformation and tensile crack propagation, increasing elastic modulus and bearing capacity. • Anchored rock shows more intense acoustic emission but smaller infrared temperature changes compared to unanchored rock. • Structural plane angle controls crack extension direction and strain evolution; rock prone to instantaneous slip failure at 45°–75° with lower strength and significant IR changes. • A shear failure criterion for anchored structural planes is established, enabling prediction of failure modes and support design.