樊玉峰,肖晓春,丁鑫,等. 岩煤接触面力学性质对组合煤岩力学行为影响机制[J]. 煤炭学报,2023,48(4):1487−1501. DOI: 10.13225/j.cnki.jccs.2022.0540
引用本文: 樊玉峰,肖晓春,丁鑫,等. 岩煤接触面力学性质对组合煤岩力学行为影响机制[J]. 煤炭学报,2023,48(4):1487−1501. DOI: 10.13225/j.cnki.jccs.2022.0540
FAN Yufeng,XIAO Xiaochun,DING Xin,et al. Influence mechanism of contact surface mechanical properties on mechanical behavior of coal rock combination[J]. Journal of China Coal Society,2023,48(4):1487−1501. DOI: 10.13225/j.cnki.jccs.2022.0540
Citation: FAN Yufeng,XIAO Xiaochun,DING Xin,et al. Influence mechanism of contact surface mechanical properties on mechanical behavior of coal rock combination[J]. Journal of China Coal Society,2023,48(4):1487−1501. DOI: 10.13225/j.cnki.jccs.2022.0540

岩煤接触面力学性质对组合煤岩力学行为影响机制

Influence mechanism of contact surface mechanical properties on mechanical behavior of coal rock combination

  • 摘要: 为明确组合煤岩力学行为及其冲击倾向性与岩煤间接触面力学性质关系,开展了组合煤岩单轴压缩试验,分析了岩煤间4种不同力学性质的接触面对组合煤岩强度、弹性模量、应变软化现象、声发射特征信号、能量累积耗散特征和冲击倾向性的影响规律,研究了接触面黏结属性和破坏情况所引起的端面效应对煤岩局部变形特征及强度的影响机制。研究结果表明:接触面力学性质对组合煤岩的力学性质有一定影响,完整的接触面增强了组合煤岩的强度和弹性模量,提高了弹性能累积能力,抑制了峰前阶段的煤岩破裂,削弱了峰后的应变软化阶段;接触面的破坏降低了端面效应的影响作用,提高了组合煤岩的破坏程度,延长了峰后的应变软化过程;无黏结型组合煤岩试样的各项力学指标均低于其余3种接触面;建立了组合煤岩本构关系并提出了考虑接触面破坏的组合煤岩强度估算方法和接触面断裂的判定方法;理论计算结果与实验结果较为一致;随着岩煤间接触面力学性质的提高,组合煤岩弹性能占比提高,塑性能占比降低;厘清了岩煤间接触面力学性质对组合煤岩冲击倾向性的影响规律,认为接触面和煤岩相对力学性质是引起组合煤岩冲击倾向性各项指标冲突的重要影响因素。

     

    Abstract: The uniaxial compression test of coal and rock combination was carried out in order to clarify the influence mechanism of the contact surface mechanical properties on the rock-burst tendency of the coal rock combination, and the contact surfaces with four different mechanical properties were considered. The variation laws of strength, elastic modulus, strain softening phenomenon, acoustic emission characteristic signal, energy accumulation and dissipation characteristics, and impact tendency of coal rock combination were analyzed. The influence mechanism of end face effect caused by the bonding properties and failure of contact surface on local deformation characteristics and strength of coal and rock was studied. The results show that the mechanical properties of the contact surface have a certain influence on the mechanical properties of the coal rock combination. The complete contact surface enhances the strength and elastic modulus of the coal rock combination, improves the elastic energy accumulation ability, inhibits the sample fracture in the pre-peak stage, and weakens the strain softening stage after the peak. The failure of the contact surface reduces the influence of the end-face effect, improves the failure degree of the coal rock combination, prolongs the post-peak strain softening process, and the strain energy density in the pre-peak stage is mainly plastic dissipation. The mechanical indexes of unbonded coal rock combination samples are lower than that of others. The constitutive relationship of coal rock combination is established, and the strength estimation method considering the contact surface failure, and the determination method of contact surface fracture are proposed. The theoretical calculation results are consistent with the experimental results. With the improvement of mechanical properties of rock coal interface, the proportion of elastic energy of combined coal increases, and the proportion of plastic property decreases. The influence law of the mechanical properties of rock coal contact surface on the rock burst tendency of coal rock combination is clarified. It is considered that the relative mechanical properties between the contact surface and coal is an important factor which causes the conflict of various indexes of coal rock combination rock burst tendency.

     

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