中文摘要：

工程上常采用不随应力变化的岩石结构面抗剪强度参数，不能反映结构面摩擦角应力效应的变化规律。为研究结构面摩擦角与法向应力的相关度，首先对中砂、水泥、硅粉、非引气型萘系减水剂等原材料的配比进行研究，获得与天然钙质板岩物理力学特性相类似的岩石模型材料，然后采用研发的结构面制作模具及其制备工艺制作10组具有不同表面起伏度和粗糙度的结构面，并利用自制的高精度岩石结构面直剪仪对系列法向应力下的结构而摩擦角进行直剪试验研究和数据统计分析，结果表明：结构面峰值摩擦角及其变化率均随法向应力的增加而降低，而不是通常认为的峰值摩擦角为定值；结构面残余摩擦角随法向应力的变化并不是很明显；具有不同起伏程度和粗糙度系数的模型结构面在相同法向应力下的峰值摩擦角也有差异；结构面峰值摩擦角应力效应和JRC-JCS（JRC为粗糙度系数，JCS为壁岩强度）准则中所确定的峰值摩擦角变化规律相一致，而且粗糙度系数越大结构面峰值摩擦角的应力效应越明显。

英文摘要：

The stress effect on friction angles of structural planes of rocks was considered. In order to obtain the relationship between peak friction angle and normal stress, modeling materials for rock similar to calcareous slate in physico-mechanical properties were obtained through studying the ratios of raw materials such as the medium sand, the cement, the silica powder, the naphthalene super-plasticizer of non-air entraining. Ten groups of rock structural planes with different waviness and roughness were made. Friction angles of the rock structural planes under different normal stresses were determined with the direct shear apparatus. Results show that the peak friction angle and its rate of variation of rock joints are decreased with the increasing of normal stress instead of a constant value generally considered. The residual friction angles of structural planes changed little with the increasing of normal stresses. The peak friction angles under the same normal stress are different for each rock model due to the differences of surface waviness and roughness of structural planes. The stress effect on peak friction angles of rock joints are the same with the variation of friction angles determined with the failure criterion of joint roughness coefficient-joint wall compressive strength（JRC-JCS）, the larger the JRC is, the more significant the stress effect on peak friction angle is.