深部邻空巷道面临强动压、高瓦斯的双重困扰。为解决深部邻空巷道严重变形问题, 以13131巷为工程背景, 采用理论分析、数值模拟、现场试验等方法, 研究了采空区侧向上覆岩层运动特征、邻空巷道围岩变形机制以及邻空巷道切顶卸压技术参数。结果表明: 6.0 m粉砂岩是上覆岩层亚关键层, 弧形三角块破断导致厚硬岩层共同运动, 致使侧向支承压力及其影响范围增大, 造成邻空巷道严重变形; 切顶卸压效果与切顶高度、切顶角度密切相关, 只有当切顶高度达到关键层顶部时, 才能有效降低邻空巷道变形量, 超过关键层高度后, 效果提升不再明显; 当切顶角度为0°时, 岩块传递的侧向支承压力最小, 切顶角度由0°增加至10°时, 邻空巷道变形量呈轻微上升趋势, 由10°增加至20°时, 邻空巷道变形量大幅增大。基于切顶关键技术参数及顶板瓦斯抽放钻孔空间分布特征, 提出了“预留超前安全距离+留设抽放钻孔保护距离+封孔长度差异化+瓦斯监测与安全保障”爆破切顶技术方案, 并开展了现场试验, 有效控制了邻空巷道变形量, 保证了顶板钻孔瓦斯抽采效果。

Deep gob-side roadways are subjected to the dual challenges of strong dynamic pressure and high gas content. To address the severe deformation of deep gob-side roadways, the 13131 roadway was used as a case study. Theoretical analysis, numerical simulation, and field testing were employed to study the movement characteristics of overlying strata on the gob side, the deformation mechanism of the surrounding rock, and the technical parameters for roof cutting and pressure relief. The results show that 6.0 m siltstone layer acts as a sub-key layer within the overlying strata. The fracture of arc-shaped triangular blocks triggers the collective movement of thick and hard strata, resulting in increased overburden load, an expanded influence range of side abutment pressure, and severe deformation of the gob-side roadway. The effectiveness of roof cutting and pressure relief depends heavily on the roof cutting height and angle. Effective reduction of roadway deformation is achieved only when the roof cutting height reaches the top of the key stratum; beyond this height, the improvement becomes negligible. At a roof cutting angle of 0°, the transmitted side abutment pressure is minimal. As the roof cutting angle of from 0° to 10°, the deformation of the gob-side roadway shows a slight increase. However, when the angle increases from 10° to 20°, the deformation increases significantly. Based on the key technical parameters of roof cutting and the spatial distribution of gas drainage boreholes, a blasting roof cutting scheme was proposed. This scheme incorporates an advanced safety distance, a protective distance for drainage boreholes, differentiated sealing lengths, and gas monitoring with safety assurance. Field tests demonstrated that this approach effectively controlled roadway deformation while maintaining gas drainage efficiency in roof boreholes.