Shear behavior of single-joint bolted sandstone subjected to dryewet cycles:Experimental and analytical approaches  

作　　者：Luobin Zheng Kaiwen Liu 

机构地区：[1]School of Resources and Environmental Engineering,Wuhan University of Science and Technology,Wuhan,430081,China [2]State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu,610059,China [3]Key Laboratory of High-speed Railway Engineering(Ministry of Education),School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China [4]Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu,610031,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第10期4216-4228,共13页岩石力学与岩土工程学报（英文）

基　　金：the Natural Science Foundation of China(Grant Nos.42302314 and 52078427);the Open foundation of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Grant No.SKLGP2022K001).

摘　　要：A series of direct shear tests under constant normal loading conditions were carried out on specimens of bolted sandstone single-joint treated with different numbers of dryewet cycles.The experimental results show that the peak shear strength and shear stiffness of bolted sandstone joints were significantly reduced after 12 dryewet cycles.The decrease in the shear strength of rough joints is more significant than that of flat joints.Due to the decrease in the strength of the surrounding rock,the deformation characteristics of the bolts are significantly affected by the number of dryewet cycles performed.With an increase in the number of dryewet cycles,the plastic hinge length of the bolt gradually increases,resulting in an increase in the corresponding shear displacement when the bolt breaks.Compared with the tensileeshear failure mode of the bolts in flat joints,the tensileebending failure mode arises for bolts in rough joints.A shear curve model describing the whole process of bolted rock joints is established based on the deterioration of rock mechanical parameters caused by dry‒wet cycles.The model proposed considers the change in the friction angle of the joint surface with the shear displacement,which is applied to the derivation of the model by introducing the dynamic evolutionary friction angle parameter.The reasonably good agreement between a predicted curve and the corresponding experimental curve indicates that this method can effectively predict the shear strength of a bolted rock joint involving rough joint under dryewet cycling conditions.

关 键 词：Reinforcement technique Interface behavior Bolted sandstone Cyclic dryingewetting Analytical model 

分 类 号：TU476[建筑科学—结构工程]