不同倾角煤岩组合体冲击破坏特征研究

Study on Impact Failure Characteristics of Coal Rock Combination with Different Angles

针对煤岩复合结构冲击地压等动力灾害的防治,选用煤与红砂岩2种材料制作节理倾角为0°、30°、60°、90°的体积比1∶1的煤岩组合体试件,利用霍普金森压杆试验系统进行动载冲击破坏特征试验。试验结果表明:煤与红砂岩及其组合体试件满足动载平衡条件,煤的动态抗压强度、破坏程度与冲击速度呈正比。煤岩组合体的抗压强度与倾角条件和受力形式密切相关。煤先受力、岩先受力2种加载方式下,抗压强度与倾角的变化曲线呈近似中心对称关系,冲击破坏形式主要为压剪破坏。为井下复合煤岩结构冲击地压防治提供一定的参考。

Focus on control of coal rock composite structure dynamic disasters such as rock burst,coal and red sandstone specimens with joint angles of°0,30°,60°,90°and volume ratio of 1∶1 are fabricated.The Hopkinson pressure bar test system is used to test the dynamic load impact failure characteristics.The test results show that the dynamic load balance condition of coal,red sandstone and its assemblage is satisfied.The dynamic compressive strength and damage degree of coal are proportional to the impact velocity.The compressive strength of coal-rock composite is closely related to the dip angle and force forms.Under the two loading modes of coal first loading and rock first loading,the change curve of compressive strength and inclination angle is approximately center symmetric.The impact failure of coal and rock assemblage under dynamic load is mainly compressive shear failure.The research can provide reference for rock burst prevention and control of underground composite coal and rock structures.