煤矿地层广泛分布有层状砂岩、煤、页岩等层状岩体，层状岩体是一种沿着层面力学性质相同、垂直层面力学性质各异的各向异性岩体，基质和层面的不同组合导致层状岩体具有尺寸效应、层理密度和层面倾角效应等结构性效应，将影响层状岩体的强度和破坏特征。针对结构性效应对层状岩体力学性质和破坏特征的影响，开展了基质的尺寸效应、层状岩体的层理密度和层面倾角效应研究，分析了结构性效应对层状岩体应力应变曲线特征、峰值强度、变形特征和破坏特征的影响。结果表明：峰值强度和弹性模量均表现出随试样高宽比增大而减小的尺寸效应；围压对尺寸效应有弱化作用，围压约束条件下，岩体结构性失稳程度减弱，延性特征逐渐显现；层面倾角为90°时层状岩体的峰值强度和弹性模量达到最大值；围压和层面倾角影响层状岩体的脆延转化特性、损伤程度和破坏形式。研究结果可为深井巷道层状围岩力学参数标定和破坏机制分析提供重要的理论依据。

Layered sandstone, coal, shale and other layered rocks are widely distributed in coal mine strata. The layered rock is an anisotropic rock with the same mechanical properties along the layer and various mechanical properties in the perpendicular direction. The different combinations of matrix and layers lead to the structural effects, such as size effect, as well as bedding density and inclination angle effect, which would affect the strength and failure characteristics of layered rocks. For the influence of structural effect on the mechanical properties and failure characteristics of layered rocks, the size effect, as well as bedding density and inclination angle effect were analyzed. The influence of structural effect on stress-strain curve characteristics, peak strength, deformation characteristics and failure characteristics was studied. The results were as follows. Both the peak strength and elastic modulus decrease with the ratio of height to width. The size effect is weakened by the confining pressure. Under the triaxial state, the structural unstability is weakened, and the ductile characters become obvious. The peak strength and elastic modulus of the layered rock mass at the inclination angle 90° approach the maximum. The confining pressure and layer inclination would affect the brittle-ductile transition characteristics, damage degree and failure form. The results could provide important theoretical basis for the calibration of mechanical parameters and analysis of failure mechanism in layered surrounding rocks in deep mining.