摘要
赵家寨煤矿开采煤层在水力割缝过程中受到较大扰动,围岩强度降低,导致煤厚较大且分布不均的“三软”煤层巷道更加难以控制。基于14205工作面岩石力学参数,理论分析确定水力割缝合理参数,借助COMSOL Multiphysics构建不同煤厚条件下水力割缝模型,数值模拟得到了水力割缝对煤层应力、位移影响规律。结果表明:顶煤厚度对于受水力割缝扰动后巷道顶板稳定性有着重要影响,应力特征的主要影响因素为割缝的形态、位置,煤层越厚其变形量越小,水力割缝对煤体的损伤范围主要与割缝位置相关,巷道受扰动范围为两帮各5 m,托顶煤为2 m厚时,顶部煤体受破坏程度最大,巷道稳定性最差,当托顶煤厚度超过4 m时巷道稳定性得到良好改善,在煤体损伤范围内巷道顶部变形量最大,需要加强支护力度。研究结果为不同厚度“三软”煤层水力割缝扰动下巷道围岩稳定性分析提供基础。
Coal seam mining in Zhaojiazhai coal mine is greatly disturbed in the process of hydraulic fracturing,and the strength of surrounding rock is reduced,which makes it more difficult to control the roadway of"three soft"coal seam with large coal thickness and uneven distribution.Based on the rock mechanics parameters of 14205 working face,the reasonable parameters of hydraulic slotting were determined by theoretical analysis.The hydraulic slotting model under different coal thickness conditions was constructed by COMSOL Multiphysics,and the influence law of hydraulic slotting on the stress and displacement of coal seam was obtained by numerical simulation.The results show that:the thickness of top coal has an important influence on the stability of roadway roof disturbed by hydraulic slotting,and the main influencing factors of stress characteristics are the shape and position of slotting.The thicker the coal seam,the smaller the deformation,the damage range of hydraulic slotting to coal body is mainly related to the slotting position.When the disturbed range of roadway is 5 m for each side,and the thickness of supporting top coal is 2 m,the top coal body is the most damaged.The roadway stability is the worst.When the thickness of the supporting top coal exceeds 4 m,the roadway stability is well improved.The roof deformation of the roadway is the largest within the scope of coal body damage,so it is necessary to strengthen the support.The research results provide a basis for the stability analysis of roadway surrounding rock disturbed by hydraulic fracturing of"three soft"coal seams with different thicknesses.
作者
黄永菲
张勇
郝浩然
HUANG Yongfei;ZHANG Yong;HAO Haoran(Henan Xinzheng Coal and Electricity Co.,Ltd.,Xinzheng 451100,China;School of Mines,China University of Mining and Technology,Xuzhou 221116,China)
出处
《煤炭技术》
CAS
2024年第2期57-62,共6页
Coal Technology
关键词
水力割缝
“三软”煤层
岩体损伤
煤层厚度
围岩稳定性
hydraulic slotting
"three soft"coal seam
rock mass damage
coal seam thickness
stability of surrounding rock
