The failure of rock in cold regions due to repeated freeze–thaw (F-T) cycles and periodic load-induced fatigue damage presents a significant challenge. This study investigates the evolution of the multi-scale structure of fractured granite under combined freeze–thaw (F-T) cycles and periodic loading and develops a constitutive damage model. The results indicate that after F-T cycles, network cracks develop around pre-existing cracks, accompanied by block-like spalling. After applying the fatigue load, the nuclear magnetic resonance (NMR) T₂ spectrum shifts to the right, significantly increasing the amplitude of the third peak. The freeze–thaw process induces a “liquid–solid” phase transition, weakening the original pore structure of the rocks and leading to meso-damage accumulation. The pores in fractured granite progressively enlarge and interconnect, reducing the rock’s load-bearing capacity and fatigue resistance. The combined effects of F-T cycles and periodic loading induce particle movement and alter fracture modes within the rock, subsequently affecting its macro-damage characteristics. The theoretical curves of the constitutive model align with the experimental data. The findings can serve as a theoretical reference for preventing and controlling engineering disasters in fractured rock masses in cold regions.

In the context where the surrounding rock of deep coal mine roadways is in a complex mechanical environment of “three highs and one disturbance”, mining disturbances are prone to cause instability and damage to the roadways, and the severe deformation of the south wing main roadway caused by mining disturbances in the 2404 working face of a certain mine in the Jiaoping Mining Area restricts safe production. In order to reduce the deformation and damage of the south wing main roadway affected by long-term dynamic pressure, this study proposes a determination method of key rock strata for top cutting pressure relief and the pressure-relief method along the stress transmission path of the south wing main roadway. It completes the design and field test of the hydraulic fracturing scheme for the hard roof of the 2404 transportation roadway, and evaluates the pressure-relief effect through means such as pressure curves, mine pressure manifestation laws, and borehole observation. The results show that hydraulic fracturing significantly weakens the strength of the roof rock strata, forms through cracks between the pressure-relief holes, reduces the average working resistance of the support by 18% after fracturing, and reduces the average pressure step distance of the roof by 34%. During the mining process, the stress variation range of the coal pillar is small, and there is no obvious deformation or damage to the surrounding rock and support structure of the south wing main roadway. It effectively cuts off the stress transmission path of the hard roof and controls the deformation of the roadway, providing technical support for the control of surrounding rock in deep dynamic pressure roadways.