The investigation into the fracture features and failure mechanisms of tunnels excavated in both shallow and deep rock masses employs a series of three-dimensional heterogeneous models that incorporate various factors such as cross-section, tunnel alignment, faults, and tunnel support systems. The rock failure process analysis method, enhanced with the strength reduction method, is utilized to simulate the gradual fracture process, identify macro failure modes, determine safety factors, and replicate the characteristic fracture phenomena observed in surrounding rock masses. Furthermore, the mechanical mechanisms and acoustic emission energy of deep rocks at different stages of the entire zonal disintegration process are delved into. The findings reveal that the zonal disintegration process is initiated by stress redistribution. The cross-section of the tunnel plays a crucial role in influencing stress buildup, stress shadow, stress transfer, and the failure mode of the surrounding rock mass. Additionally, the dip of faults and the tunnel support system can alter the zonal disintegration pattern near the tunnel surface along their strikes. The presence of twin tunnels further complicates the zonal disintegration pattern. These insights contribute significantly to our understanding of zonal disintegration in deep engineering projects.