摘要
长平煤矿4302工作面为承压水上厚煤层放顶煤开采,为预防回采期间底板突水事故,对采动的工作面底板破坏深度和应力进行分析研究,据工作面地质和生产实际条件,采用弹塑性理论和回归分析方法确定了回采对底板破坏深度的影响范围,利用UDEC数值模拟软件模拟了底板破坏方式和应力分布规律,通过现场布置钻孔应力计和钻孔窥视,实测了回采期间底板应力变化规律和破坏区域。结果表明,底板岩性及其组合结构、回采工艺是影响底板破坏的主要因素,实测、理论计算、数值模拟计算得出底板破坏深度分别为6,9.50～9.75和8m,实测破坏深度小于理论计算和数值模拟结果,底板岩石强度为强—弱—强的组合结构,中部软岩层弱化了上部硬岩层应力集中,同时使下部硬岩层受力均匀,起到良好的保护底板破坏的作用。
No.4302 coal mining face of Changping Mine was a top coal caving mining face in a thick seam with pressurized water bearing in below strata.In order to prevent the floor water inrush accident occurred during the coal mining period,an analysis and study was conducted on the face floor failure depth and stress caused by the mining activities.According to the actual geology and production of the coal mining face,the elasticity and plasticity theory and the regression analysis method was applied to determinate the mining affected to the floor failure depth.The UDEC numerical simulation software was applied to simulate the floor failure mode and floor stress distribution law.With the borehole stressmeter and in-borehole peeper set at the mine site,the floor stress variation law and the failure area during the mining period was measured at the mine site.The results showed that the floor lithology and its combined structure as well as the mining technique would be the main factors affected to the floor failure.The floor failure depths of the site measured,theoretical calculation and the numerical simulated calculation would be individually as 6 m,9.50 ~ 9.75 m and 8 m.The site measured failure depth was less than the theoretical calculation and numerical simulation results.The floor rock strength was a strong-weak-strong combined structure.The soft rock stratum in the middle section of the floor weakened the stress concentration in the top hard rock stratum.Thus the bottom hard rock stratum of the floor was evenly stressed and could play a good role to protect the floor failure.
出处
《煤炭科学技术》
CAS
北大核心
2010年第12期17-21,共5页
Coal Science and Technology
关键词
综采放顶煤
底板应力
破坏深度
防治水
数值模拟
fully mechanized top coal caving mining
floor stress
failure depth
mine water prevention and control
numerical simulation
