应力加载下采煤工作面卸压钻孔裂隙演化特征  

Fractures Evolution Characteristics of Pressure Relief Boreholes in Coal Mine Working Face under Stress Loading

作　　者：魏高明 刘森[3] 易欣 刘红亮 孙国桢[3] WEI Gaoming;LIU Sen;YI Xin;LIU Hongliang;SUN Guozhen(College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;Key Laboratory of Western Mining Disaster Prevention and Control,Ministry of Education,Xi'an University of Science and Technology,Xi'an 710054,China;Shandong Energy Group Northwest Mining Co.,Ltd.,Pingliang 744000,China)

机构地区：[1]西安科技大学安全科学与工程学院,西安710054 [2]西安科技大学西部矿井开采及灾害防治教育部重点实验室,西安710054 [3]山东能源集团西北矿业有限公司,甘肃平凉744000

出　　处：《煤炭技术》2025年第1期1-6,共6页Coal Technology

基　　金：国家自然科学基金青年科学基金项目(5240042179);陕西省教育厅重点协同创新项目(22JY041)。

摘　　要：采煤工作面卸压钻孔漏风诱发的煤自燃隐患威胁矿井安全生产,研究应力加载下采煤工作面或沿空预留煤柱卸压钻孔裂隙演化特征,对有效指导煤自燃预防具有重要意义。采用理论分析和实验测试相结合的研究方法,研究了3种含孔试件在单轴应力加载过程中的应力-应变曲线,分析和划分了试件破坏过程,确定了不同应力加载下,试件孔周围裂隙发育形态分布规律和孔周裂隙位移量。结果表明:相比完整煤试件,在各项应力加载下含孔煤试件的峰值应力强度平均降低55.49%,峰值应力超过6 MPa含孔煤试件孔周围出现T形裂隙。随着外加载应力增大,孔周裂隙扩展延伸至试件发生形变破坏,试件孔周边出现大量裂隙网络,外界应力加载过程中,试件沿孔周的径向位移和环向位移均大于0.5 mm。表明含孔试件在载荷应力作用下卸压钻孔发生形变破坏,产生大量毫米尺度的裂隙网络,在钻孔周围松动圈未及时采取裂隙封堵措施的状况下,容易长时间漏风供氧而发生煤自燃隐患。The hidden danger of coal spontaneous combustion induced by air leakage in pressure relief boreholes of coal mining faces threatens the safety production of mines.Revealing the evolution characteristics of fractures in the pressure relief boreholes of coal mining faces or reserved coal pillars under stress loading is of great significance for effectively guiding the prevention of coal spontaneous combustion.Adopting a research method combining theoretical analysis and experimental testing to study the stress-strain curves of three types of specimens with the holes during a uniaxial stress loading.The failure process of the specimens is analyzed and divided,thereby the distribution pattern of fracture development and the number of fractures around the holes are determined under different stress loading rates.Resulting shows that compared with intact coal specimens,the peak stress intensity of porous coal specimens decreased by an average of 55.49% under various stress loads,and T-shaped fractures appeared around the coal specimens with peak stress exceeding 6 MPa.With the external stress increases,the fractures around the hole expand and extend until the specimen undergoes deformation and failure.Thus,countless of fracture networks appear around the hole,the radial and circumferential displacements of the specimen along the hole during the external stress loading process are both greater than 0.5 mm.This indicates that under the action of load stress,deformation and damage occur in the depressurization boreholes,resulting in a large scale of millimeter scale fracture networks.Without timely fracture sealing measures taken in the loose circle around the boreholes,it is easy to cause long-term air leakage and oxygen supply,leading to the hidden danger of coal spontaneous combustion.

关 键 词：煤自燃 卸压钻孔 形变破坏 裂隙发育 漏风供氧 

分 类 号：TD313[矿业工程—矿井建设]