岩体节理面的刚度系数、黏结力和内摩擦角是反映节理面力学特性的重要参数。基于含不同倾角节理岩样的三轴压缩试验,通过对标准岩样的应力-位移分析,由互等功原理,建立节理岩样应变与位移新的几何关系,推导出弹性状态下节理刚度系数解析解,根据摩尔-库仑强度理论得出节理面的黏结力和内摩擦角。为了检验方法的正确性,对含节理面的同类岩体进行直接剪切试验,测出节理面的法向刚度、切向刚度、黏结力和内摩擦角。结果表明,两种方法所得结果基本吻合,说明所提出的方法可以通过节理岩样三轴压缩试验及理论分析间接得到岩体节理面的刚度系数、黏结力和内摩擦角,实现了节理岩体力学参数的简捷、快速测定。
The stiffness coefficients,cohesion,friction angle are the important parameters in reflecting the mechanical characteristics of the joints.Based on the tri-axial compressive tests for rock mass samples containing different joint angles and analysis to stress and displacement,the analytic solutions of stiffness coefficients in the elastic state can be deduced by establishing the new equations of strain and displacement according to the reciprocal work principle;and the cohesion and the friction angle of joints are obtained by the Mohr-Coulomb strength theory.In order to verify the validity of the presented method,the direct shear tests for the rock mass samples containing the similar natural joints are implemented;and the normal stiffness,the shear stiffness,the cohesion,the friction angle of the joints are obtained.The comparative results show that the parameter values obtained by the given method are close to those by the direct shear tests.Thus,the stiffness coefficients,cohesion,friction angle of the rock joints can be got by the tri-axial compressive test,and the parameters can be concise-fleetly measured.