School of Civil Engineering, Xi’an University of Architecture and Technology
Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering
Institute of Tunnel and Underground Structure Engineering, Xi’an University of Architecture and Technology
School of Civil Engineering, Yancheng Institute of Technology
The First Engineering Co., Ltd., of China Railway 20th Bureau Group Corporation

针对考虑层理倾角的硬质砂岩力学行为及破裂响应特征问题，对不同层理倾角的硬质砂岩进行单轴压缩试验，深入探究层理倾角对硬质砂岩力学行为的影响以及层理倾角与碎块分形特征之间的关系。试验结果表明：(1) 层理倾角对硬质砂岩应力−应变曲线的类型特征无显著影响，但倾角较小时(0°、22.5°、45.0°)，曲线表现为单峰变化规律，倾角较大时(67.5°、90.0°)，曲线表现为多峰变化规律，且曲线波动位置主要位于峰值附近。(2) 峰值应力σd和峰值应变εd均在倾角为67.5°(最不利层理结构面)时达到最小值46.25 MPa和9.80×10−3，层理倾角对硬质砂岩应力的影响明显大于应变，受层理倾角的影响，硬质砂岩的各向异性度为1.32~1.64，表现出低各向异性特征。(3) 硬质砂岩随着层理倾角的增大呈现出剪切破坏−剪切张拉复合破坏−层理结构面剪切破坏−劈裂破坏的损伤破坏演化规律；单轴压缩下硬质砂岩的碎块质量特征和分形特征明显，硬质砂岩碎块以中块分布为主，层理倾角对细粒碎块的质量分布影响较小，其分形维数值位于1~2，碎块较大比例分布在大尺寸分布区间。研究结果可为含层理结构面岩石的稳定性及地下空间工程灾害防治提供理论参考。

This study focuses on the mechanical behavior and failure responses of hard sandstones considering bedding dip angles. Through uniaxial compression tests of hard sandstones with different bedding dip angles, this study delved into the influence of bedding dip angles on the mechanical behavior of hard sandstones and the relationship between the bedding dip angles and fractal characteristics of hard sandstone fragments. The test results show that bedding dip angles produced negligible effects on the type of the stress-strain curves of hard sandstones. However, low dip angles (0°, 22.5°, and 45°) corresponded to unimodal curves, while high dip angles (67.5° and 90°) were associated with multimodal curves, with curve fluctuations primarily approaching peaks. At a dip angle of 67.5° (the most unfavorable bedding plane), peak stress σd and peak strain εd reached their minimum values of 46.25 MPa and 9.80×10−3, respectively. Bedding dip angles displayed more significant effects on the stress than on the strain of hard sandstones. Under the influence of bedding dip angles, hard sandstones manifested low anisotropy, with anisotropy degrees ranging from 1.32‒1.64. With an increase in the bedding dip angle, hard sandstones experienced the damage failure evolution from shear failure to shear-tension compound failure, then the shear failure of bedding planes, and finally splitting failure. Under uniaxial compression, hard sandstone fragments displayed distinct mass and fractal characteristics, dominated by moderate-size fragments. Furthermore, bedding dip angles had negligible effects on the mass distribution of fine-grained fragments, which exhibited fractal dimensions from 1−2. Additionally, a large proportion of fragments measured large sizes. The results of this study can serve as a theoretical reference for research on the stability of rocks with bedding planes and the disaster prevention and control of underground space engineering.

国家自然科学基金项目(52178393，51878549)；陕西省创新能力支撑计划项目(2020TD-005)

宋战平，刘洪珂，郑方，等. 考虑层理倾角的硬质砂岩力学行为及破裂响应特征[J]. 煤田地质与勘探，2023，51(12)：167−175.

SONG Zhanping，LIU Hongke，ZHENG Fang，et al. Mechanical behavior and failure response characteristics of hard sandstones considering bedding dip angles[J]. Coal Geology & Exploration，2023，51(12)：167−175.