(1. School of Civil Engineering and Architecture，Anhui University of Science and Technology，huainan，Anhui 232000，China；2. Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering，Guilin，Guangxi 541004，China；3. School of Civil Engineering，Jiangxi University of Engineering，Xinyu，Jiangxi 338029，China；4. State Key Laboratory of Rock and Soil Mechanics，Wuhan Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China；5. Yellow River Engineering Consulting Co.，Ltd.，Zhengzhou，Henan 450000，China；6. Powerchina Huadong Engineering Corporation Limited，Hangzhou，Zhejiang 310000，China)
Abstract：In order to solve the problem of large deformation of crushed surrounding rock，grouting support is generally used as an effective means to prevent engineering disasters. For the artificial sawtooth structure surface，the laboratory direct shear test was carried out for the reinforcement of ungrouting and different water-cement ratio aluminate cement grouting，and the mechanism of grouting reinforcement was revealed. The results show that the grouting support can improve the peak strength，cohesion and interface stiffness of the structural surface. With the increase of water-cement ratio，the shear peak strength decreases under the same normal stress. With the increase of water-cement ratio，the cohesion of interface decreases. Interface failure forms：the sawtooth is composed of different relief angles. In the case of shear failure of the ungrouting interface，the modes are shear，wear，slope climbing and gnawing coupling effects. When shear failure occurs at the interface after grouting，the curve fluctuation amplitude is large after the peak strength，and the failure is transformed from failure of bonding force to failure of slip. The characteristics of grouting slip failure are similar to those of ungrouting interface failure. The normal displacement and shear displacement curves show that the ungrouting structural surface is mainly dilatancy，and the grouting structural surface shows the characteristics of first shrinking and then dilatancy.
2021, Vol. 40 
