School of Mechanics and Engineering, Liaoning Technical University
Institute of Disaster Rock Mechanics, Liaoning Uni-versity
School of Environment, Liaoning University
School of Mining Engineering, LiaoningTechnical University
Jilin Longjiapu Mining Co., Ltd.

锚杆支护与钻孔卸压等方式改变巷道围岩介质属性,形成具有三介质两结构面的巷道梯度围岩结构,增加对应力波的吸收与衰减能力,防止巷道冲击破坏。为揭示巷道梯度围岩结构中应力波传播衰减规律,建立了梯度围岩结构应力波透射模型,从弹性波在介质交界面处的波场分解和能量分配角度出发,分析了卸压带密度以及应力波入射角度对能量系数的影响,发现梯度围岩卸压带的密度和入射角对各折反射波的能量系数具有显著影响,揭示了梯度围岩结构的吸能防冲力学机理。基于不同梯度围岩结构模型的数值计算,综合应力波的波幅衰减系数、波阻抗匹配系数、能量吸收占比、能量衰减系数等参量,对比分析巷道梯度围岩结构对应力波传播衰减的影响规律。研究结果表明:梯度围岩结构卸压带宽度增加,应力波振动频率降低,波幅衰减系数随之增加,能量衰减系数呈上升趋势,提高了梯度围岩结构的缓冲与隔震性能,增强了巷道的防冲能力;卸压带宽度较小时,会引起应力波在梯度结构中的复杂叠加,使得应力波在局部区域幅值激增,合理的卸压带宽度能够避免应力波在三介质两结构面结构中的复杂叠加。卸压带内钻孔间排距减小,梯度围岩结构卸压带中介质的弹性模量与密度下降,能量吸收占比增加,提高了对应力波的吸波性能。梯度围岩结构中“三带”的波阻抗匹配系数越大,能量衰减系数越大,即“三带”的介质性质差异越大,梯度围岩对于应力波的吸收衰减效果越好,通过调控卸压钻孔的深度与间排距改变卸压带的尺寸和物理力学性能,可有效提高梯度围岩结构的吸波、缓冲、隔震性能。结合工程实例分析证实了梯度围岩结构可有效吸收冲击地压产生的应力波能量,避免冲击地压灾害发生。

Rock bolt support and borehole pressure relief change the medium properties of roadway surrounding rock,form the roadway gradient surrounding rock structure with three media and two planes, increase the absorption and attenuation ability of stress waves, and prevent the impact damage of roadway. In order to reveal the attenuation law of stresswave propagation in roadway gradient surrounding rock structure, the stress wave transmission model of gradient surrounding rock structure is established, and the mechanism of energy absorption and burst prevention of gradient surrounding rock structure is revealed from the aspect of wave field decomposition and energy distribution of elastic wave at the interface of different medium. The influence of the density of relief zone and the incident angle of stress wave on the energycoefficient is analyzed. It is found that the density of relief zone and the incident angle of gradient surrounding rock cansignificantly affect the energy coefficient of each refraction wave. Based on the numerical calculation of different gradientsurrounding rock structure, the influence law of gradient surrounding rock structure on stress wave propagation attenuation is analyzed by integrating the amplitude attenuation factor, wave impedance matching factor, energy absorption ratio,and energy attenuation factor. The results show that as the width of the pressure relief zone of the gradient surroundingrock structure increases, the vibration frequency of the stress wave decreases, the amplitude attenuation factor increases,and the energy attenuation factor shows an upward trend, which improves the cushioning and seismic isolation performance of the gradient surrounding rock structure and enhances the burst prevention ability of roadway. When the width ofthe pressure relief zone is small, the complex superposition of stress waves in the gradient structure will be formed, whichmakes the amplitude of stress waves surge in the local region. Reasonable width of pressure relief zone can avoid the complex superposition of stress waves in the structure with three media and two planes. The row spacing between boreholes inthe pressure relief zone decreases, the elastic modulus and density of the medium in the pressure relief zone of the gradient surrounding rock structure decrease, and the proportion of energy absorption increases, which improves the absorbingperformance of the stress wave. The greater the wave impedance matching factor of the three zones in the gradient surrounding rock structure, the greater the energy attenuation factor, that is, the greater the difference in the medium properties of the three zones, the better the attenuation effect of the gradient surrounding rock structure on stress waves. The sizeand physical and mechanical properties of the pressure relief zone can be changed by adjusting the depth and row spacingof the pressure relief boreholes, which can effectively improve the wave absorption of the gradient surrounding rock structure, cushioning, and seismic isolation performance. Combining with engineering case analysis, it is proved that the surrounding rock with gradient structure can effectively absorb the stress wave energy generated by rock burst and avoid rockburst disasters.

国家自然科学基金面上资助项目(51974150);辽宁省“兴辽英才计划资助项目”(XLYC2007025);国家重点研发计划资助项目(2022YFC3004605)

王爱文,孙郑齐,潘一山,等. 梯度围岩结构应力波透射模型与传播衰减规律[J]. 煤炭学报,2023,48(5):1969−1984.

WANG Aiwen, SUN Zhengqi, PAN Yishan, et al. Transmission model and propagation attenuation law ofstress wave in gradient surrounding rock structure[J]. Journal of China Coal Society,2023,48(5):1969−1984.