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于永江,刘佳铭,杨云涛,等. 基于能量原理不同含水率下煤岩体变形破坏能量损伤演化机制[J]. 煤炭科学技术,2024,52(6):67−80. doi: 10.12438/cst.2023-1871
引用本文: 于永江,刘佳铭,杨云涛,等. 基于能量原理不同含水率下煤岩体变形破坏能量损伤演化机制[J]. 煤炭科学技术,2024,52(6):67−80. doi: 10.12438/cst.2023-1871
YU Yongjiang,LIU Jiaming,YANG Yuntao,et al. Mechanical properties and damage constitutive model of coal with different water content based on energy principle[J]. Coal Science and Technology,2024,52(6):67−80. doi: 10.12438/cst.2023-1871
Citation: YU Yongjiang,LIU Jiaming,YANG Yuntao,et al. Mechanical properties and damage constitutive model of coal with different water content based on energy principle[J]. Coal Science and Technology,2024,52(6):67−80. doi: 10.12438/cst.2023-1871

基于能量原理不同含水率下煤岩体变形破坏能量损伤演化机制

Mechanical properties and damage constitutive model of coal with different water content based on energy principle

  • 摘要: 为探究不同含水率下煤岩体在变形破坏过程中的能量演化规律与损伤演化特征,对双马一矿煤岩体开展了在不同含水率条件下单轴压缩试验,基于能量计算及最小耗能原理,分析不同含水率下煤岩体能量耗散特征及损伤演化机制,结果表明:不同含水率下煤岩体力学性质不同,峰值应变与含水率呈正相关,抗压强度、弹性模量与含水率呈负相关;煤岩体含水率越高,其在峰值处弹性应变能及破坏吸收总应变能越小,耗散能占总应变能比例越高;基于最小耗能原理建立的损伤本构模型表明:随着煤岩体含水率增加,损伤门槛值逐渐降低;干燥状态下,煤岩体在应力峰值处损伤变量分别为0.36、0.28,当含水率增至自然状态时,煤岩体在应力峰值处损伤变量值分别下降0.09、0.18,但当含水率增至饱水状态时,煤岩体在应力峰值处损伤变量值反而分别大幅度上升0.102、0.49,总体呈先减后增的发展趋势;进一步建立了不同含水率煤岩损伤应变能释放率演化模型,低含水率煤岩较干燥煤岩的最大损伤应变能释放率大幅度下降,降幅分别为45.61%、31.29%,而随着含水率增加至饱水状态,其最大损伤应变能释放率增大幅度较平缓,分别为3.08%、8.80%,表明煤岩破坏剧烈程度并未大幅度增加。研究成果对煤岩矿柱水害预测评价与岩石损伤评估具有一定参考意义。

     

    Abstract: In order to explore the energy evolution law and damage evolution characteristics of coal and rock mass in the process of deformation and failure under different water content, the uniaxial compression test of coal and rock mass in Shuangma No.1 Coal Mine under different water content conditions was carried out. Based on the principle of energy calculation and minimum energy consumption, the energy dissipation characteristics and damage evolution mechanism of coal and rock mass under different water content were analyzed. The results show that the mechanical properties of coal and rock mass under different water content are different, and the peak strain are positive correlated with water content, compressive strength and elastic modulus are negatively correlated with water content. The higher the water content of the coal and rock mass, the smaller the elastic strain energy at the peak value and the total strain energy absorbed by the failure, and the higher the proportion of the dissipated energy to the total strain energy. The damage constitutive model based on the principle of minimum energy consumption shows that the damage threshold value gradually decreases with the increase of water content of coal and rock mass. In the dry state, the damage variables of coal and rock mass at the peak stress are 0.36 and 0.28, respectively.When the water content increases to the natural state, the damage variables of coal and rock mass at the peak stress decrease by 0.09 and 0.18, respectively.However, when the water content increases to the saturated state, the damage variables of coal and rock mass at the peak stress increase by 0.102 and 0.49, respectively, showing a trend of decreasing first and then increasing.The evolution model of damage strain energy release rate of coal rock with different water content is further established. The maximum damage strain energy release rate of low water content coal rock is significantly lower than that of dry coal rock, and the decrease is 45.61% and 31.29% respectively. With the increase of water content to saturated state, the maximum damage strain energy release rate changes gently, which is 3.08% and 8.80% respectively, indicating that the damage severity of coal rock does not increase significantly.

     

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