李兵, 贺虎, 徐大连, 等. 2021. 深部采掘扰动区线性切顶防冲护巷技术[J]. 工程地质学报, 29(4): 1131-1138. doi: 10.13544/j.cnki.jeg.2021-0534.
    引用本文: 李兵, 贺虎, 徐大连, 等. 2021. 深部采掘扰动区线性切顶防冲护巷技术[J]. 工程地质学报, 29(4): 1131-1138. doi: 10.13544/j.cnki.jeg.2021-0534.
    Li Bing, He Hu, Xu Dalian, et al. 2021. Linear roof cutting for rockburst prevention and roadway protection in deep mining disturbed area[J]. Journal of Engineering Geology, 29(4): 1131-1138. doi: 10.13544/j.cnki.jeg.2021-0534.
    Citation: Li Bing, He Hu, Xu Dalian, et al. 2021. Linear roof cutting for rockburst prevention and roadway protection in deep mining disturbed area[J]. Journal of Engineering Geology, 29(4): 1131-1138. doi: 10.13544/j.cnki.jeg.2021-0534.

    深部采掘扰动区线性切顶防冲护巷技术

    LINEAR ROOF CUTTING FOR ROCKBURST PREVENTION AND ROADWAY PROTECTION IN DEEP MINING DISTURBED AREA

    • 摘要: 采掘扰动是诱发冲击地压灾害的重要因素,深部采掘扰动区域则受冲击与巷道变形的双重威胁,针对该技术难题,本文研究了线性密集切顶防冲护巷技术。基于关键层理论分析了倾斜煤层关键层倾向破断结构特点,表明关键块B的空间状态是控制正在开采的工作面与迎采巷道矿压显现的关键,给出了采掘扰动工况下的最佳关键块断裂线位置。基于COMSOL模拟研究了不同装药直径下的应力峰值分布规律,结果表明:爆破后应力以指数函数形式快速衰减,给出了不同装药直径下应力峰值分布的拟合公式;致裂半径与装药直径呈幂函数的正相关关系;以顶板岩石抗拉强度为指标值,确定了爆破孔直径对应的最优间距。现场设计实施了不同技术参数的切顶方案,结果表明,相比于传统的深孔爆破,线性密集切顶两钻孔之间能够形成贯通裂隙,从而控制关键层的破断方式,因此钻孔间距是影响防冲与护巷效果的关键参数。通过巷道围岩观测与微震监测,表明线性密集切顶技术能够有效减弱迎采巷道的围岩变形,同时降低正在开采的工作面矿压显现与冲击危险性,现场实践验证了理论与模拟结果,可为类似条件工程提供借鉴。

       

      Abstract: The disturbance between workface mining and roadway extraction is the main key factor that inducing rockburst disasters in the coal mines. The deep area is disturbed by large roadway deformation besides rockburst. Aiming to solve this common technical challenge,this paper proposes the linear roof cutting technology. Based on the key strata theory,firstly we analyze the structure characteristics of the key strata of inclined coal seam and reveal that the spatial occurrence of the key block B is critical for rockburst and surrounding rock control. Then the optimal fracture line of key block B of the inclined coal seam is suggested. Using the COMSOL software we simulate the rules of stress distribution after blasting with different charge diameters. The results show that the stress peak exponentially attenuates,and the fracturing area is positively correlated with the charge diameter in a power function. The fitting formula for the fracture zone under different charge diameters is obtained. Take the tensile strength of the roof rock as the index value,the optimal distance corresponding to the charge diameter can be determined. We design different in-situ schemes based on the geological conditions. The field experiments verify that the linear roof cutting technology has a significant effect on rockburst prevention and roadway protection,comparing to the traditional deep hole roof blasting since the crack can be penetrated between two adjacent blasting holes. So,the most important parameter for roof cutting is the distance of blasting holes. Through the displacement observation and microseismic monitoring,it is shown that the linear roof cutting technology can effectively reduce the deformation of the surrounding rock of the gob-side roadway,and at the same time reduce the rockburst of the working face. Field practice has verified the theoretical and simulation results,and provides a valuable reference for similar engineering.

       

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