1.China Coal Research Institute,Beijing ,China;2.National Key Lab of Coal Resources HighEfficient Mining and Clean Utilization,Beijing ,China

为研究水平应力加载下煤岩的强度及变形特征,在试验室开展了不同应力条件下真三轴压缩破坏试验。试验结果表明:试件的三轴压缩峰值强度随最小水平应力和垂直应力的增大而增大,为比较复杂应力水平下煤岩力学特性,定义“等效围压”表述应力状态,得到试件峰值强度及峰值应变均随等效围压的增大呈线性增大;煤岩破坏产生的裂隙数量随着等效围压增大而增多;试件破坏程度随着等效围压的增大而增强且破断角随等效围压增大成二次函数递增。煤体所处应力水平影响其力学特性,试验结果对于煤岩深部高效开采及安全生产有重要的理论支持和实践意义。

In order to study the strength and deformation characteristics of coal and rock under horizontal stress loading,the true three axis test was carried out under different stress conditions in laboratory.The test results show that the peak strength of three axis compression increases with the increase of the minimum principal stress and vertical stress,defined the“equivalent confining pressure”to describe the mechanical properties of coal should be under the stress level,the peak strength and the complex peak strain of the specimens increase linearly with the increase of the equivalent confining pressure; the number of cracks produced by the failure of coal and rock increases with the increase of equivalent confining pressure and the breaking angle increases with the increase of equivalent confining pressure into two times.The stress level of coal affects its mechanical properties,the test results have important theoretical support and practical significance for efficiency mining and safe production of deep coal and rock.