## 6 Conclusions  
1. The clarification of the gob-side entry retention and roof-cutting parameters under typical geological conditions in karst mountainous areas is crucial for the stability of the surrounding rock. Based on this, by integrating the variation characteristics of coal seam burial depth and the non-uniform load distribution state of the roof in karst mountainous areas, a mechanical model of the cantilever beam structure for gob-side entry retention and roof cutting is constructed. By introducing the theory of limit equilibrium, the superposition principle, and fracture line theory, the differentiated stress distribution of the roof caused by coal seam burial depth is correlated with the parameters of roof-cutting height and angle. Taking the geological conditions of Anshun Coal Mine as an example, by substituting relevant parameters and comparing the increments of tensile stress under burial depth intervals of 50 m, roof-cutting height intervals of 1 m, and roof-cutting angle intervals of 5\({}^{\circ}\), it is found that the influence of roof-cutting height > the influence of roof-cutting angle > the influence of coal seam burial depth. Considering the impact of the correlation among the three factors on the long-term stability of gob-side entry retention, it is necessary to select appropriate roof-cutting parameters in different coal seam burial depth areas to avoid insufficient or excessive roof-cutting issues. 2. Taking the tensile strength of 7.2 MPa of the main roof as the threshold, the critical values and reasonable ranges of roof-cutting height and roof-cutting angle under different burial depths are provided. The reasonable range of roof-cutting parameters exhibits a fan-shaped distribution feature. As the coal seam burial depth increases, the fan-shaped zone of reasonable roof-cutting parameters gradually decreases. As the roof-cutting height increases, the selectable range of roof-cutting angles gradually increases. Based on the geological conditions of Anshun Coal Mine, it is concluded that effective roof cutting cannot be achieved when the roof-cutting height is less than 4.5 m. When the roof-cutting height is between 4.5 and 8 m, the selectable range of roof-cutting angles is between 0 and 28.5\({}^{\circ}\). 3. Through three-dimensional numerical simulation analysis, the displacement and stress evolution characteristics of the surrounding rock of the retained roadway under different roof-cutting parameter schemes within a reasonable range were explored. It was found that a smaller cutting angle results in greater sliding resistance between the cuts, leading to larger displacement and stress on the retained roadway roof. Conversely, a larger cutting angle prolongs the drilling cycle, impacting the progress of underground construction. Analyzing the safety factor of the roadway using the strength reduction method, it was observed that within the same burial depth range, as the cutting height and cutting angle increase, the safety factor of the roadway gradually increases, but the rate of increase gradually decreases. Therefore, when determining the roof-cutting parameters, it is essential to comprehensively consider the balance between drilling construction costs and roadway stability. Overall, a cutting angle of 10\({}^{\circ}\) is considered reasonable. Furthermore, corresponding roof-cutting height schemes of 6 m, 7 m, and 8 m were proposed for burial depths of less than 400 m, between 400 m and 500 m, and greater than 500 m, respectively. The roadway stability coefficients under these three schemes are higher than those of other schemes within the same burial depth range, with values of 2.02, 1.96, and 1.88, respectively. 4.