吉东亮,程辉,赵洪宝,等. 冲击扰动下岩石蠕变损伤演化与失稳诱发机制[J]. 煤炭学报,2024,49(S1):197−207. DOI: 10.13225/j.cnki.jccs.2023.0184
引用本文: 吉东亮,程辉,赵洪宝,等. 冲击扰动下岩石蠕变损伤演化与失稳诱发机制[J]. 煤炭学报,2024,49(S1):197−207. DOI: 10.13225/j.cnki.jccs.2023.0184
JI Dongliang,CHENG Hui,ZHAO Hongbao,et al. Creep damage evolution and instability induction mechanism of rock under impact disturbance[J]. Journal of China Coal Society,2024,49(S1):197−207. DOI: 10.13225/j.cnki.jccs.2023.0184
Citation: JI Dongliang,CHENG Hui,ZHAO Hongbao,et al. Creep damage evolution and instability induction mechanism of rock under impact disturbance[J]. Journal of China Coal Society,2024,49(S1):197−207. DOI: 10.13225/j.cnki.jccs.2023.0184

冲击扰动下岩石蠕变损伤演化与失稳诱发机制

Creep damage evolution and instability induction mechanism of rock under impact disturbance

  • 摘要: 为研究冲击扰动下岩石的蠕变损伤机理,基于复杂应力下的蠕变方程模型,同时考虑煤岩材料的非均质性,结合Weibull分布构建能够描述煤岩蠕变全过程的蠕变损伤本构模型,并进行参数的敏感性分析。进一步分析了不同初始蠕变应力下受到不同扰动能量时冲击扰动对煤岩蠕变破坏的影响。对复合煤岩体蠕变过程中受冲击扰动破坏进行了模拟分析,讨论不同初始角度煤岩体下蠕变损伤的失稳诱发机制。结果表明:基于复杂应力下的蠕变模型,考虑煤岩介质弹性模量和强度的非均质性建立的蠕变损伤本构模型能够较好地描述煤岩3阶段蠕变特性;蠕变模型中参数Am0n0对煤岩的蠕变特性的影响主要表现为其值越大,煤岩越易发生加速蠕变破坏;当蠕变加载时,随轴向加载应力的增大,瞬时的弹性应变会明显增大;当蠕变应力相同时,冲击荷载越大,煤岩越易发生蠕变,从而越易发生破坏;当冲击荷载相同时,随蠕变应力的增大,煤岩的破坏时间也会明显减小;对于复合煤岩体,蠕变初始阶段进行冲击时应变率出现了明显增加,当蠕变处于稳定阶段再次冲击时应变率幅值较小,最终复合煤岩体发生加速蠕变直至失稳。随着节理角度的增加,蠕变时间先减小后增大,其中节理角度为90°时煤岩体蠕变时间最长,达到75 h。

     

    Abstract: In order to study the creep damage mechanism of composite coal rock mass under impact disturbance, based on the creep equation model under complex stress and considering the heterogeneity of coal and rock materials, a creep damage constitutive model which can describe the whole process of coal and rock creep was constructed in combination with Weibull distribution, and the sensitivity analysis of parameters was carried out. Furthermore, the influence of impact disturbance on rock creep failure under different initial creep stresses and different impact energy was analyzed. The impact disturbance failure of composite coal rock mass in the creep process was simulated and analyzed. The instability inducing mechanism of creep damage under different initial angles was discussed. The results show that the creep damage constitutive model based on the damage mechanics theory, with the maximum tensile strain criterion and the molar Coulomb criterion as the damage criterion, can describe the three-stage creep characteristics of coal rock well. In the creep model, the influence of parameters A, m0 and n0 on the creep characteristics of coal rock is mainly manifested as that the larger the parameters are, the more likely the coal rock is to have accelerated creep failure. Under creep loading, the instantaneous elastic strain increases obviously with the increase of axial loading stress. When the creep stress is the same, the larger the impact load is, the more likely the coal rock is to creep and thus the more likely it is to fail. When the impact load is the same, the failure time of coal rock will decrease obviously with the increase of creep stress. For the composite coal rock mass, the strain rate increases obviously when the initial creep stage is impacted. When the creep is in the stable stage, the strain rate amplitude is smaller, and finally the composite coal rock mass accelerates creep until it becomes unstable. With the increase of joint angle, the creep time firstly decreases and then increases. When the joint angle is 90°, the maximum creep time of coal mass reaches 75 h.

     

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