MODEL EXPERIMENT STUDY ON THE DIFFERENT REINFORCEMENT EFFECTS OF UN-BONDED ANCHOR CABLE AND FULL-LENGTH BONDED ANCHOR CABLE IN ROCK ENGINEERING

The different reinforcement effects of the two typical anchor cables—un-bonded anchor cable and full-length bonded anchor cable are studied by model experiments of the underground openings and the shear strength of rock mass structural planes. The different reinforcement effects and characteristics of the two typical anchor cables are analyzed and compared by the excavation displacement,failing loads,load-displacement characteristics,strain distribution characteristics of the underground opening wall and the macroscopic damage process of the openings and etc.. By shear tests of reinforced specimen with structural planes and that without structural planest,he different reinforcement effects of the two typical anchor cables on rock mass structural planes are compared. The comparison results of peak shear strength of the reinforced specimen and the variation characteristics of the tensile force of the two typical anchor cables in shearing process are given. The tensile force of the un-bonded anchor cable increases with the shear displacement;however,the tensile force of the full-length bonded anchor cable has almost no change in shearing process. Based on the comprehensive comparison of the reinforcement effects of the two typical anchor cables,some suggestions on the design of reinforcement engineering are put forward.