错层位外错式巷道位置选择及联合支护研究

Location selection and combined support of external staggered roadway with staggered mining

  • 摘要: 针对新巨龙煤矿1301综放工作面区段间留设煤柱尺寸较大造成的资源浪费和回采巷道支护困难等问题,本文提出采用错层位外错式巷道布置方案,建立错层位非常规煤柱力学模型,利用极限平衡理论分析了非常规煤柱应力环境和极限平衡区特征;考虑不同错距下沿底巷道所处应力环境及区段煤柱弹性应变能密度分布特征,确定下区段沿底巷道合理错距为3.0 m;同时引入区段间相邻巷道联合支护方案,对实际地质条件下接续工作面回采阶段区段间相邻巷道联合支护方案和传统支护方案进行模拟验证。结果表明:区段间相邻巷道联合支护方案优于传统支护方案,峰值应力由80 MPa降至64 MPa,降低率为20 %,表明其对巷道围岩控制更为有效;区段煤柱单位留设面积为111.5 m2,相较于传统支护方案区段煤柱的170 m2,降低率为34.4 %。研究结果对减少区段煤柱留设尺寸和提高煤炭回采率起到积极的推动作用。

     

    Abstract: This study proposes a layout scheme for external staggered roadway and builds a mechanical model for unconventional coal pillars with staggered positions as a solution to the waste of resources caused by the large coal pillar size between the sections of 1301 fully mechanized top coal caving face and the difficulty in supporting the roadway in Xinjulong Coal Mine. We analyzed the stress environment and characteristics of the extreme equilibrium zone of unconventional coal pillars using the limit equilibrium theory. For the bottom roadway, the reasonable horizontal staggered distance in the lower section is set at 3.0 meters after considering its stress environment at different horizontal offset conditions and the distribution of elastic strain energy density of the section coal pillars. Meanwhile, we proposed a joint support scheme for adjacent roadways between sections. We simulated and verified the original support scheme and the joint support scheme in actual geological conditions during the mining stage of the continuous working face. Results show that the joint support scheme for adjacent roadways between sections outperforms the original support scheme. The peak stress of the joint support scheme reduced from 80 MPa to 64 MPa, with a reduction rate of 20 %, indicating that the it is more effective in controlling the surrounding rock of the roadway. Moreover, the unit reserved area of coal pillars in the section was 111.5 m2, which is a 34.4 % reduction from 170 m2 in the original support scheme. This study offers implications for reducing the reserved size of coal pillars in fewer sections and improving the coal recovery rate.

     

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