深井高地应力煤岩互层薄顶板区段蠕变煤柱合理宽度数值研究

Numerical Study on Reasonable Width of Creep Pillar in Coal-rock Interbedded Thin-roof Section of Deep-well and High-stress

为确定受深井高地应力及蠕变破坏影响的煤岩互层薄顶板工作面区段煤柱的合理宽度,采用现场实测、理论分析及数值模拟等方法进行研究,通过现场窥视及地应力测试确定工作面顶板类型为煤岩互层薄顶板;通过弹性核计算公式确定区段煤柱宽度为29. 56 m;经数值模拟论证当煤柱宽度为20、25、30 m时,其弹性核区宽度分别为4、15、22 m,占煤柱宽度的20. 0%、60. 0%、73. 3%。研究结果表明:宽30 m煤柱能够保证巷道稳定使用,顶板结构、高地应力、蠕变破坏及动压影响是巷道变形严重的主要原因。巷道经掘进及采动影响蠕变计算后,位移曲线可分为4个区域,即初始蠕变区(Ⅰ)、衰减蠕变区(Ⅱ)、稳定蠕变区(Ⅲ)、采动加速蠕变区(Ⅳ),相应的煤柱应力曲线形状为孤峰型、平台型、马鞍型。

In order to determine the reasonable width of section coal pillars in the working face of coal-rock interbedded thin-roof under the influence of deep-well and high-stress and creep failure,the method of field measurement,theoretical analysis and numerical simulation were adopted to carry out the research,through field peep and stress test,the roof type of the working face was determined to be the thin interbed roof of coal and rock;the width of section coal pillar was determined as 29.56 m by elastic core formula;numerical simulation showed that when the coal pillar width was 20 m,25 m and 30 m,the elastic core area width was 4 m,15 m and 22 m respectively,accounting for 20.0%,60.0%and 73.3%of the coal pillar width.The research results show that 30 m coal pillar can ensure the stable use of roadway,and roof structure,high stress,creep failure and the influence of dynamic pressure are the main reasons of roadway deformation.With the influence of roadway tunneling and mining on creep calculation,the displacement curve can be divided into four areas,namelyⅠinitial creep zone,Ⅱdecay creep zone,Ⅲstable creep zone,Ⅳmining acceleration creep zone,the corresponding curve shapes of coal pillar stress are solitary peak type,platform type and saddle type.