碳中和愿景下煤炭行业发展的危机与应对

含预制裂隙的煤岩，在外载荷作用下具有与完整煤岩不同的力学特性及破坏特征。采用金刚石线切割法对完整煤岩试样进行不同倾角(30°、45°、60°)的三维宏观裂隙预制，通过单轴与三轴压缩试验，结合声发射监测手段，进行裂隙煤岩在不同加载条件下的强度、变形、破坏模式、裂隙扩展规律和声发射特征的研究，探究具有冲击倾向性裂隙煤岩失稳破坏的规律。结果表明：完整煤岩强度、弹性模量与围压具有良好的线性关系，围压从0~16 MPa，强度提升了400%，其破坏模式为剪切破坏，剪切角度呈增大趋势。预制裂隙的存在降低煤岩强度，30°、45°、60°裂隙煤岩强度分别降低了13%、24%、37%，破坏时由裂隙尖端扩展翼型新裂隙，新裂隙沿最大主应力方向扩展与预制裂隙汇合贯通，煤岩发生失稳破坏。裂隙煤岩在围压增大到一定水平时发生“逆围压效应”，即围压越大，强度劣化越明显，当围压达到8 MPa，3种裂隙煤岩强度均降低了200%。完整煤岩在破坏阶段声发射强度达到极值，裂隙煤岩因裂隙扩展发育在各阶段会产生声发射信号激增点，可根据此判断裂隙煤岩的破坏程度及所处应力状态。

How to handles the crisis of coal industry in China under the vision of carbon neutrality

Coal rock with prefabricated fractures has different mechanical properties and failure characteristics from intact coal rock under external loading. The three-dimensional macro fracture prefabrications of intact coal rock samples with different dip angles(30°, 45°, and 60°)were carried out by diamond wire cutting method. Through uniaxial and triaxial compression tests and combined with acoustic emission monitoring techniques, the strength, deformation, failure mode, fracture propagation law and acoustic emission characteristics of the fractured coal rocks under different loading conditions were studied. The law of instability and failure of fractured coal rock with impact tendency were explored. The results show the follows. The strength and elastic modulus of intact coal rock have a good linear relationship with confining pressure. The strength increases by 400% as the confining pressure increases from 0 MPa to 16 MPa. The failure mode is shear failure and the shear angle increases. The existence of prefabricated fractures reduces the strength of coal rock. The strength of 30°, 45°and 60°fractured coal rocks decreases by 13%, 24% and 37%, respectively. When the failure occurs, the new wing fractures expand from the fracture tip along the direction of maximum principal stress and join the prefabricated fracture, resulting in instability failure of the coal rock. When the confining pressure of fractured coal rock increases to a certain level, the