煤岩单轴与三轴压缩试验研究

Experimental Study of Coal Rock Uniaxial and Triaxial Compression

在电液伺服岩石力学试验系统上进行了煤岩的单轴和三轴压缩试验。结果表明:在单轴压缩时,大部分试件表面出现剥落并发生X状共轭斜面剪切破坏或劈裂破坏;不同试样煤岩的强度离散性较大,对于强度较高的试件,其弹性模量也较大。三轴压缩时,煤岩的变形增加并沿某一斜面产生剪切破坏,变形表现出塑性材料的特征;煤样弹性模量相对单轴压缩时提高,离散性降低;三轴强度大于单轴强度,而且三轴强度和残余强度随围压的增加而增大。

Coal rock uniaxial and triaxial compression experiments were carried out with the electro-hydraulic servo rock mechanics test system.The results showed that the surface spalling of most specimens appeared,X-shaped conjugate slant shear failure and splitting failure occurred in uniaxial compression experiment.The coal rock strength of different samples presented larger discreteness,and the elastic modulus was also larger for the specimen with higher strength.In triaxial compression experiment,the deformation of coal rock increased and shear failure along a slant occurred,the deformation exhibited the characteristics of plastic material.The elastic modulus of coal samples increased compared to uniaxial compression experiment and the discreteness reduced.Triaxial compressive strength was greater than uniaxial compressive strength.Triaxial compressive strength and residual strength increased with confining pressure increasing.