Energy evolution is of great significance for exposing the failure mechanism of coal reservoirs and evaluating the fracturing effect. This study conducted uniaxial compression experiments with bedding intersection angle (θ) as a variable, calculated the energy and analyzed their controlling effects on coal deformation, failure and brittleness. The results show that, with increase in θ, the failure mode of coal changes from tensile fracture to shear failure, and the strength, elastic energy (U^e) and total energy (U) of coal all show a trend of first decreasing and then increasing. Based on the comprehensive criteria of the elastic energy ratio (U^e/U) and stress–strain curve, a new division method of the compression stage is proposed, and the determination of the critical point between stages can avoid the influence of human subjective factors. The transformation of U^e and external loads jointly provides the energy source for the release of dissipated energy (U^d). U^e is the main energy type in the pre-peak stage, and a significant amount of energy is converted into U^d in the failure stage. A new brittleness index was constructed by utilizing the relationship between U^e and U^d. It was found that brittleness is negatively correlated with θ and positively correlated with U^e/U at the peak point. A model of the mechanical strength of coal with structured planes has been constructed and validated by experimental data, which can be used to analyze the effect of structural planes on coal strength. When the hydraulic fracturing direction is parallel or at a low angle to the bedding plane, it is favorable for the formation of extensive fractures.

能量演化对于揭示煤储层破坏机理、评价压裂效果具有重要意义。本研究以层理交角（θ）为变量进行单轴压缩实验，计算能量并分析其对煤变形、破坏和脆性的控制作用。结果表明，随着θ的增大，煤体的破坏模式由拉伸破坏转变为剪切破坏，煤体的强度、弹性能( U ^e )和总能量( U )均呈现先减小后减小的趋势。增加。基于弹性能量比（U ^e /U）和应力应变曲线的综合准则，提出了一种新的压缩阶段划分方法，阶段间临界点的确定可以避免人为主观因素的影响。U ^e和外部负载的变换共同为耗散能量（ U ^d ）的释放提供能量来源。U ^e是峰值前阶段的主要能量类型，在故障阶段大量能量转化为U ^d 。利用U ^e和U ^d之间的关系构建了新的脆性指数。结果发现，脆性与峰值处的θ呈负相关，与U ^e / U呈正相关。建立了具有结构面的煤体力学强度模型，并通过实验数据进行了验证，可用于分析结构面对煤体强度的影响。当水力压裂方向与层理面平行或成小角度时，有利于大面积裂缝的形成。