To accurately predict coal burst hazards and estimate the failure of coal pillars in underground coal mining systems, it is of great significance to understand the mechanical behavior of coal-rock bimaterial composite structures. This paper presents experimental and numerical investigations on the response of rock-coal, coal-rock, and rock-coal-rock bimaterial composite structures under triaxial compression. The triaxial compression experiments are conducted under confining pressures in the range of 0–20 MPa. The resulting inside fracture networks are detected using X-ray-based computed tomography (CT). The experimentally observed data indicate that the mechanical parameters of the rock-coal-rock composites are superior to those of the rock-coal and coal-rock combinations. After compression failure, the coal-rock combination specimens are analyzed via X-ray CT. The results display that the failure of the coal-rock composite bodies primarily takes place within the coal. Further, the bursting proneness is reduced by increasing confining pressure. Subsequently, the corresponding numerical simulations of the experiments are carried out by using the particle flow code. The numerical results reveal that coal is vulnerable with regard to energy storage and accumulation.

为了准确预测煤矿井下采煤系统中的煤爆危险和估算煤柱破坏，了解煤岩双材料复合结构的力学行为具有重要意义。本文介绍了岩石-煤，煤-岩石和岩-煤-岩双材料复合结构在三轴压缩下的响应的实验和数值研究。在限制压力为0至20 MPa的范围内进行三轴压缩实验。使用基于X射线的计算机断层扫描（CT）可以检测出最终的内部骨折网络。实验观察的数据表明，岩-煤-岩石复合材料的力学参数优于岩-煤和煤-岩组合的力学参数。压缩失败后，通过X射线CT分析煤岩组合标本。结果表明，煤岩复合体的破坏主要发生在煤内部。此外，通过增加围压降低了爆裂倾向。随后，通过使用粒子流代码进行实验的相应数值模拟。数值结果表明，煤炭在能量存储和累积方面很脆弱。