冻结裂隙煤岩单轴压缩破坏机制及细观参数反演

Failure mechanisms under uniaxial compression and microscopic parameter inversion of frozen fractured coal rock

煤岩的变形破坏是一个复杂的渐进演化过程,为了研究冻结条件下裂隙煤岩的破坏机理,基于CT扫描图像,应用三维离散元模拟方法,建立了冻结裂隙煤岩的单轴压缩模型。对比分析数值试验与室内压缩试验得到的应力-应变曲线,发现二者吻合较好。通过对数值模拟结果的系统分析,得到了冻结裂隙煤岩的细观结构损伤过程和宏观变形破坏规律,也发现了煤岩的弹性模量和强度随温度变化的发展规律,同时给出了煤岩强度和弹性模量与温度的数学关系式。以上研究表明,离散元模拟方法能够为研究冻结裂隙煤岩的细观损伤演化和宏观破坏变形提供新思路,可为岩体工程的安全稳定分析提供理论依据和参数基础。

Deformation and failure of coal rock is a complicated and gradual evolution process.In order to study the failure mechanisms of frozen cracked coal,a uniaxial compression model of frozen cracked coal was established based on CT machine images and using 3-D discrete element method.The numerical stress-strain curves were compared with experimental ones,which showed that there was in good agreement between the numerical and experimental results.Then,the micro-structure damage and failure processes of the cracked coal were analyzed.Simultaneously,the development law and mathematical relationship between the strength and elastic modulus of coal rock and temperature was obtained.Through above studies,a new idea is found to analyze damage failure of frozen cracked coal by discrete element method.The idea and method in this study may be useful for studying other discrete materials.