层面位置对煤岩组合体动态破坏过程及力学特性具有重要影响作用，但影响规律尚不清晰。

通过对含有3种层面位置的煤岩组合体(层面分别位于岩石部分上位、中位和下位)开展霍普金森冲击(split Hopkinson pressure bar，SHPB)实验，分析了冲击载荷条件下煤岩组合体动态应力−应变、破坏过程、能量结构、碎块特征的演变规律。

结果表明：(1)煤岩组合体动态应力−应变过程可以分为近似线性阶段、非线性的动态应力−应变阶段、弹性模量降低阶段、宏观破裂阶段、应力波卸载阶段5个阶段。(2)随着层面由上向下布置，岩石部分的破坏程度逐渐增强，破坏过程逐渐剧烈，破坏后的碎块的均匀程度降低，而煤体部分的破坏程度则逐步降低，破碎后的块度逐渐增加。(3)层面的存在会降低煤岩组合体动态抗压强度，与无层面煤岩组合体(平均强度为79.487 MPa)相比，当层面位于上方时，组合体动态抗压强度(平均强度为73.724 MPa)降低7.25%；当层面位于中位时，组合体动态抗压强度(平均强度为61.798 MPa)降低22.26%；当层面位于下位时，组合体的动态抗压强度(平均强度为64.991 MPa)降低18.24%。(4)随着层面位置由上向下布置，能量结构发生变化，反射能占比降低，吸收能占比增加，透射能占比减小。本研究可以为超长孔水力压裂技术或地面压裂技术在大范围处理坚硬顶板工程开展过程中压裂位置的选择提供一定指导。

The bedding plane location significantly impacts the dynamic failure processes and mechanical properties of coal-rock composites, but the specific influence patterns remain unclear.

Dynamic mechanical tests were conducted on coal-rock composite specimens with bedding planes located at the top, middle, and bottom using the split Hopkinson pressure bar (SHPB). The investigation focused on the dynamic stress-strain behavior, failure process, energy distribution, and fragmentation characteristics under impact loading conditions.

The findings indicate that: (1) The dynamic stress-strain behavior of coal-rock composites can be segmented into five distinct stages: near-linear stage, nonlinear dynamic stress-strain stage, elastic modulus reduction stage, macroscopic rupture stage, and stress wave unloading stage. (2) As the bedding plane location transitions from top to bottom, the extent of rock damage increases, the failure process becomes more pronounced, and the uniformity of post-failure fragments decreases. Conversely, the coal component exhibits a reduction in damage severity and an increase in fragment size after failure. (3) The presence of a bedding plane significantly reduces the dynamic compressive strength of coal-rock composites. Compared to composites without a bedding plane (average strength: 79.487 MPa), the dynamic compressive strength decreases by 7.25% (average strength: 73.724 MPa) when the bedding plane is at the top, by 22.26% (average strength: 61.798 MPa) when at the middle, and by 18.24% (average strength: 64.991 MPa) when at the bottom. (4) The energy distribution changes as the bedding plane location shifts from top to bottom, with a reduction in reflected energy, an increase in absorbed energy, and a decrease in transmitted energy. These results provide valuable insights for optimizing fracturing positions in large-scale hard roof treatment using ultra-long hole hydraulic fracturing or surface fracturing techniques.