含软弱夹层倾斜结构面的剪切特性与倾斜角、充填度密切相关, 为了获得具有起伏形貌的含软弱夹层倾斜结构面的剪切特性, 采用多功能岩土体接触破损测试系统, 开展了针对起伏形貌的含软弱夹层倾斜结构面试样的直剪试验。试验结果表明: ①不含软弱夹层的倾斜结构面剪应力–剪切位移曲线具有峰值剪断特征; 含软弱夹层倾斜结构面剪应力–剪切位移曲线具有滑动破坏特征。②充填度不同时, 倾斜结构面法向位移随剪切位移增大而增大, 变化率逐渐增大并趋于稳定, 呈剪胀效应特征; 倾斜角不同时, 结构面法向位移均随着剪切位移的增大而增大, 并且法向位移前期增长率明显小于后期增长率。③倾斜结构面抗剪强度 随充填度的增大呈负指数减小; 随倾斜角和法向应力的增大近似呈线性增大。④考虑软弱夹层材料、充填度及倾斜角对抗剪强度的影响, 在Barton抗剪强度模型的基础上, 建立了适用于含软弱夹层倾斜结构面抗剪强度模型。研究成果可为工程岩体稳定性评价提供参考。

The shear behavior of inclined rock joint containing weak interlayers are closely related to the dip angle and degree of infill. To obtain the shearing characteristics of inclined rock joint with undulating morphologies containing weak interlayers, direct shear tests were conducted on samples of inclined rock joint with such morphologies using a multifunctional geotechnical contact-destruction testing system. The results show that the shear stress-shear displacement curves of inclined rock joint without weak interlayers exhibit peak shear fracture characteristics, while those containing weak interlayers show sliding failure characteristics. Under varying degrees of infill, the normal displacement of inclined rock joint increases with increased shear displacement, with the rate of change gradually increasing and stabilizing, showing a dilation effect. Under different dip angles, the normal displacement of rock joint with shear displacement, and the early growth rate of normal displacement is significantly less than the latter. The shear strength of inclined rock joint shows a negative exponential decrease with increasing degree of infill, an approximately linear increase with an increasing dip angle, and an approximate linear increase with increasing normal stress. Considering the impact of weak interlayer material, degree of infill, and dip angle on shear strength, a new model for shear strength suitable for inclined rock joint containing weak interlayers was established based on the Barton shear strength model. The research findings can provide a reference for evaluating the stability of engineering rock masses.