以神东矿区复合煤层开采条件为研究对象,对采空区、区段煤柱下回采工作面矿压显现特殊规律进行深入研究,构建了区段煤柱下采煤工作面静载模型与动载模型;在静载模型中推导了上组煤与下组煤的应力解算方法;在动载模型中计算了因采动破坏、煤柱失稳导致上组煤基本顶岩块垮落所带来的附加载荷,分析了采煤工作面进出区段煤柱时对液压支架受力的影响规律。以神东哈拉沟煤矿工作面地质条件与采动条件建立了数值模拟模型,模拟采煤工作面进出煤柱时顶煤压力变化规律,经分析煤壁前方5~10m处顶板应力监测数据,得到出煤柱比进煤柱应力提高超10%以上的结论;该结论一方面验证了动载模型推导的合理性,另一方面也为动载模型中进出煤柱动载系数的选择提供依据。神东哈拉沟煤矿工作面对即将经过的B煤柱区采取水力压裂卸压措施进行岩层软化卸压处理,现场实测数据表明进出B煤柱其液压支架阻力由A煤柱区域的22333kN减小至19616kN,周期来压步距由21.7m减小至18.28m,有效缓解了进出区段煤柱其压力变化对液压支架支护状态的影响,研究成果可以为相同或相似条件下的煤层开采提供一定的参考和借鉴。

Taking the complex mining conditions of Shendong mining area as the research object, and the special rules of mining pressure behavior under the goaf and district coal pillars were studied. The static load model and dynamic load model of the mining face under the coal pillars of the section were constructed. The stress calculation method of the upper coal and lower coal was derived in the static load model. In the dynamic load model, the additional load caused by the collapse of the main roof rock block of the upper coal due to the mining damage and coal pillar instability was calculated, and the influence of entering and leaving the district coal pillar on the hydraulic support force was analyzed. Based on the geological and mining conditions of the working face of Halagou Coal Mine in Shendong, a numerical model was established to simulate the variation law of the coal roof pressure when the mining face was entering and exiting the coal pillars. By analyzing the monitoring data of the roof stress 5~10 m in front of the coal wall, the conclusion was drawn that the stress increase of the out-coal pillar was more than 10% higher than that of the in-coal pillar. This conclusion not only verifies the rationality of the dynamic load model derivation but also provides a basis for the selection of dynamic load coefficients for entering and exiting coal pillars. The B coal pillar area that the working face is about to pass through is treated with hydraulic fracturing and pressure relief measures to soften the rock layers and reduce pressure. The field measurement data shows that the resistance of the hydraulic support when entering and exiting the B coal pillar is reduced from 22333 kN in the A coal pillar area to 19616 kN, and the periodic weighting interval is reduced from 21. 7 m to 18. 28 m, effectively alleviating the influence of pressure changes in the entering and exiting district coal pillars on the hydraulic support state.