单轴压缩下边坡裂隙青砂岩冻融损伤力学特性研究

Study on Mechanical Properties of Fractured Cyan Sandstone with Freeze-thaw Damage in Slope under Uniaxial Compression

为了研究寒区边坡裂隙岩体的力学特性,对不同倾角和宽度的预制裂隙青砂岩开展了冻融循环试验和单轴压缩测试。结果表明:冻融循环对于该类岩石的应力-应变曲线有较大影响,主要表现为冻融循环后孔隙和裂隙的闭合阶段应变更大,且其占比也更多,而峰值应力则降低。峰值强度、弹性模量与裂隙倾角和宽度呈线性正相关,与冻融次数呈非线性负相关,初始的冻融循环对于青砂岩的劣化效果更为显著;相对于裂隙宽度,裂隙倾角的减小对于试样的峰值强度和弹性模量的劣化效果更显著。裂隙青砂岩试件主要表现为单斜面破坏,随冻融次数的增加,其破裂程度加剧,产生了更多的轴向裂纹。

In order to study the mechanical properties of fractured rock masseson slopes in cold re⁃gion,freeze-thaw cycles and uniaxial compression tests were conducted on sandstone specimens with differ⁃ent inclination angles and widths of pre-cracks.The results show that the freeze-thaw cyclehas a great influ⁃ence on the stress-strain curve of this type of rock,mainly manifested as a greater strain in the closure stage of pores and cracks after freeze-thaw cycles,and its proportion is also higher,while the peak stress decreas⁃esaccordingly.The peak strength and elastic modulus are linearly positively correlated with the inclination angle and width of the pre-crack,and nonlinear negatively correlated with the freeze-thaw cycle,and the initial freeze-thaw cycles have a more significant deterioration effect on the sandstone.Compared with the pre-crack width,the decrease of pre-crack inclination angle has more obvious deterioration effect on the peak strength and elastic modulus of the specimen.The pre-cracked sandstone specimen mainly manifested as single-inclined plane failure,and with the increase of freeze-thaw cycles,the degree of fracture intensi⁃fies,resulting in more axial cracks.