重复采动回采巷道变形机理及稳定控制
Deformation mechanism and stability control of repeated mining roadway
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摘要:
工作面在高强度开采过程中,回采巷道围岩的稳定性控制至关重要。针对布尔台煤矿厚煤层综放工作面回采巷道受强采动围岩变形特征,以42203综放工作面为例,根据巷道围岩蝶形破坏理论,与数值模拟方法相结合对其辅运顺槽受一次采动、二次采动时围岩变形机理进行了研究,分析了巷道围岩的塑性区"蝶形"扩展机理。研究结果表明:巷道围岩塑性区边界与巷道埋深、侧压系数及围岩的力学特性有关;围压比值决定着围岩塑性区的发育形态。在采动影响作用下,巷道周边最大主应力和最小主应力的大小及方向处于不断变化过程中。42203工作面辅运顺槽在受采动影响时应力发生偏转,致使塑性区呈现出非对称性扩展。基于42203工作面辅运顺槽受采动应力分布规律与塑性区演化规律,提出了相应的围岩控制加强支护技术方案,在现场工业性试验效果良好,为重复采动巷道围岩的变形机理及稳定控制提供一定借鉴。
Abstract:In the process of high intensity mining,the stability control of surrounding rock of mining roadway is very important.Aiming at the deformation characteristics of surrounding rock of mining roadway under strong mining in fully mechanized caving face of thick coal seam in Buertai Coal Mine,taking 42203 fully mechanized caving face as an example,according to the butterfly failure theory of surrounding rock of roadway,combined with numerical simulation method,the deformation mechanism of surrounding rock when the auxiliary transportation gateway is affected by primary and secondary mining is studied,and the "butterfly" expansion mechanism of plastic zone of surrounding rock of roadway is analyzed.The results show that the plastic zone boundary of roadway surrounding rock is related to the buried depth,lateral pressure coefficient and mechanical properties of surrounding rock;the ratio of confining pressure determines the development form of plastic zone of surrounding rock.Under the influence of mining,the size and direction of the maximum and minimum principal stress around the roadway are constantly changing.The stress of auxiliary transportation crossheading of 42203 working face is deflected when affected by mining,resulting in asymmetric expansion of plastic zone.Based on the distribution law of mining-induced stress and the evolution law of plastic zone in auxiliary transport crossheading of 42203 working face,the corresponding technical scheme of strengthening support for surrounding rock control is put forward.The field industrial test results are good,which provides some reference for the deformation mechanism and stability control of surrounding rock in repeated mining roadway.