Friction properties of rock are closely connected with the anisotropy.The anisotropy of rock friction can provide a valuable assessment for geotechnical and geological engineering.In this study,the rotary friction tes...Friction properties of rock are closely connected with the anisotropy.The anisotropy of rock friction can provide a valuable assessment for geotechnical and geological engineering.In this study,the rotary friction tests were conducted to analyze the water effect on the friction property and the friction anisotropy of the four types of rock.The drilling response model(DD-model)was employed to characterize the rotary friction behavior of the rocks.The parameters of this model include the three types of friction parameters:1/ς,μ,and f,where 1/ςandμare constant,and f is a variable.A quantitative method is proposed for assessing the anisotropy of rock friction.The results of the rotary friction tests indicate that the relation between torque force and thrust force conforms to the DD-model.The changes of two friction constants 1/ςandμfrom dry state to water-saturated state suggest that the water effect on the friction strength of the rocks exhibits significant anisotropy.The friction strength determined by the friction variable f increases first,then decreases,and finally stabilizes with the increasing of depth.AIf is an anisotropy index calculated by the proposed method.The percentage difference of the average value of AIf between water-saturated and dry states shows the degree of the water effect on the friction anisotropy of the rocks,mudstone(MU)>granite(GR)>fine sandstone(FS)>argillaceous siltstone(AS).The quantitative model is hopefully constructed for characterizing the relation between the anisotropic friction strength of rock and the moisture state in future.展开更多
基金sponsored by the National Natural Science Foundation of China(Grant nos.42177158,11902249,and 11872301)Key Research and Development project of Shaanxi Province(Grant no.2022SF-412)+4 种基金Education Bureau of Shaanxi Province Scientific Research Plan Projects of Shaanxi Education Department in China(Grant no.20JS093)Opening fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Chengdu University of Technology)(Grants no.SKLGP2022K005)Higher Education Basic Science(Natural Science)Research Project of Jiangsu Province in China(Grant no.23KJD410002)Yangzhou Green Yang Golden Phoenix Plan(Grant no.2408008/022)Yangzhou Science and Technology Project(Grant no.YZ2021166).
文摘Friction properties of rock are closely connected with the anisotropy.The anisotropy of rock friction can provide a valuable assessment for geotechnical and geological engineering.In this study,the rotary friction tests were conducted to analyze the water effect on the friction property and the friction anisotropy of the four types of rock.The drilling response model(DD-model)was employed to characterize the rotary friction behavior of the rocks.The parameters of this model include the three types of friction parameters:1/ς,μ,and f,where 1/ςandμare constant,and f is a variable.A quantitative method is proposed for assessing the anisotropy of rock friction.The results of the rotary friction tests indicate that the relation between torque force and thrust force conforms to the DD-model.The changes of two friction constants 1/ςandμfrom dry state to water-saturated state suggest that the water effect on the friction strength of the rocks exhibits significant anisotropy.The friction strength determined by the friction variable f increases first,then decreases,and finally stabilizes with the increasing of depth.AIf is an anisotropy index calculated by the proposed method.The percentage difference of the average value of AIf between water-saturated and dry states shows the degree of the water effect on the friction anisotropy of the rocks,mudstone(MU)>granite(GR)>fine sandstone(FS)>argillaceous siltstone(AS).The quantitative model is hopefully constructed for characterizing the relation between the anisotropic friction strength of rock and the moisture state in future.
