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针对不同强度煤、岩单元建立4种不同强弱组合的岩-煤-岩三元体串联模型。通过对强-弱交界面的应力状态分析,建立交界面附近区域强、弱体的三轴压缩强度;基于三维快速朗格朗日元法,强、弱体均采用Coulomb-Mohr剪切破坏和拉伸破坏的复合应变软化模型,数值模拟4种不同组合三元体模型在不同围压下的应力-应变曲线特征,分析不同组合的剪切破坏带及塑性破坏区随围压的变化趋势。结果表明:强-弱组合体交界面的层间约束作用会派生出附加应力,导致交界面附近区域强体强度变弱,弱体强度增强;弱胶结软岩体和煤体在单轴压缩下呈现拉剪破坏,表现出明显的应变软化行为,随着围压的增大,拉伸破坏消失,向整体剪切破坏发展,但不同组合下的破坏带数目及破坏区域不同。该研究对地震、岩爆、矿山冲击地压等灾害机理研究具有重要指导意义。
A series of rock-coal-rock ternary series models with different combinations of strength and strength are established for different strength coal and rock units. Based on the stress state analysis of the strong-weak interface, the triaxial compressive strength of strong and weak bodies in the vicinity of the interface is established. Based on the fast 3D Langrange method, the Coulomb-Mohr shear failure and extension The strain-softening model was used to numerically simulate the stress-strain curves of four different combinations of ternary models under different confining pressures. The shear stress-strain curves of different combinations of shear failure zones and plastic failure zones were analyzed. The results show that the layer-confinement interaction between strong and weak composites will generate additional stress, which will lead to the weakening of the body strength near the interface and the strengthening of the weak body. The weakly cemented soft rock mass and the coal body appear under uniaxial compression Tensile shear failure shows obvious strain softening behavior. As the confining pressure increases, the tensile failure disappears and the whole shear failure develops. However, the number of the damaged belt and the damage area are different under different combinations. The study is of great significance to the study of disasters such as earthquakes, rockburst and mine rockburst.