节理表面形貌是影响节理抗剪强度的重要因素之一。采用试验方法研究岩石节理表面形貌与其抗剪强度之间的关系;运用RYL-600岩石剪切流变仪对天然岩石节理在不同法向应力下进行剪切试验,得到不同法向应力下节理的抗剪强度曲线,并运用TALYSURF CLI 2000扫描仪将节理表面在每次剪切前后进行高精度激光扫描测试,得到岩石节理表面的三维扫描图。分析节理在不同法向应力作用下的抗剪强度与节理表面形貌变化的关系,计算岩石节理表面轮廓平均角的加权平均值θ^-p,发现随着法向应力的增加,节理峰值抗剪强度增加,随着剪切次数增加,θ^-p呈减小趋势。说明节理的抗剪强度与法向应力和节理表面形貌特征参数θ^-p有关。
The morphology of joint surface is one of the key factors affecting shear strength of joint.Relationships between morphology of joint surface and shear strength of joint are studied experimentally.Shear tests of natural rock joint under different normal stresses are conducted with RYL-600 rock shear-rheological instrument,and the relationships between shear stress and shear displacement under different normal stresses are obtained.Topographical measurements are carried out prior to and after shear tests with TALYSURF CLI 2000;3D scanning images of joint surface are obtained.Relationships between shear strength of joint under different normal stresses and morphology characteristic evolution of joint surface is analyzed.The weighted average of the mean profile angles of rock joint surface is firstly computed.It is found that the peak shear strength increases with normal stress;and the average of the mean profile angles decreases with the increase in the number of times of shear tests.It is shown that the shear strength of joint is concerned with normal stress and weighted average of mean profile angles of joint surface.