不同界面倾角下煤岩组合体强度及破坏特征分析

Strength and Failure Characteristics of Coal Rock Assemblage under Different Interface Dip Angles

开采深部煤炭时,煤层与顶底板相互作用更加明显,影响工作面安全生产。针对此问题,基于离散元方法,采用PFC2D建立了煤岩组合体试样,分析了不同界面倾角下煤岩组合体强度及破坏特征。结果表明,随着煤岩界面倾角的增加,煤岩组合体试样的峰值强度近似线性减小,弹性模量非线性增加,起裂应力和峰值应变规律性较差,AE计数的峰值逐渐降低,且AE事件出现阶段提前,试样破坏形态逐渐由“V”字形向沿界面倾角破坏转变,且裂纹具有更强的贯穿能力。

In deep coal mining,the interaction between coal seam and roof and floor is more obvious,which affects the safety production of the working face.In view of this problem,The sample of coal-rock assemblage was established using PFC2D.the strength and failure characteristics of coal rock combination under different interface dip angles are analyzed based on the discrete element method.The results show that with the increase of the coal rock interface inclination,the peak strength of the coal rock combination specimen decreases approximately linearly,the elastic modulus increases nonlinearly,the regularity of crack initiation stress and peak strain is poor,the peak value of AE count gradually decreases,and the AE event occurs earlier,the failure mode of the specimen gradually changes from"V"shape to failure along the interface inclination,and the crack has stronger penetration ability.