无煤柱自成巷开采顶板预裂爆破切缝作用机制及试验研究

Mechanism and experimental study of roof pre-splitting blasting for automated roadway formation without coal pillars

  • 摘要: 为探究无煤柱自成巷开采顶板预裂爆破对覆岩运移的影响机制,开展了顶板预裂爆破实施与否2种工况条件下相似材料模拟对比试验,分析了预裂爆破后覆岩承载结构的力学响应特征,结合所提出的沉降观测线变形分析方法,系统对比2种工况的覆岩运移关键参数。研究结果表明,顶板预裂爆破对覆岩运移的影响主要体现在强化覆岩垮落碎胀效应、弱化覆岩裂断损伤效应以及重塑覆岩裂断空间效应3个方面。根据采空区地表原位钻孔监测获得的冲洗液漏失量、钻进速度、岩芯状态等数据,验证了理论分析与模拟试验结果。该研究结论为无煤柱自成巷开采条件下岩层运移精准控制、安全高效开采及矿区生态环境保护提供了科学依据与理论支撑。

     

    Abstract: To investigate the influence mechanism of roof pre-splitting blasting on overlying strata movement in automated roadway formation without coal pillars, the mechanical response characteristics of the bearing structure of the overlying strata after pre-splitting blasting were analyzed. Comparative similar material simulation tests were conducted under two working conditions: with and without roof pre-splitting blasting. Combined with the proposed deformation analysis method based on settlement observation lines, key parameters of overlying strata movement under the two conditions were systematically compared. The results demonstrate that the influence of roof pre-splitting blasting on overlying strata movement is mainly reflected in three aspects: enhancing the caving and bulking effect of the overlying strata, weakening the fracturing and damage effect of the overlying strata, and reshaping the spatial effect of overlying strata fracturing. Based on in-situ borehole monitoring data obtained from the goaf surface, including flushing fluid loss, drilling speed, and core condition, the theoretical analysis and simulation test results were further validated. This study provides a scientific basis and theoretical support for precise control of strata movement, safe and efficient mining, and ecological environmental protection in mining areas under the condition of automated roadway formation without coal pillars.

     

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