A comprehensive understanding of the dynamic frictional characteristics in rock joints under high normal load and strong confinement is essential for ensuring the safety of deep engineering construction and mitigating...A comprehensive understanding of the dynamic frictional characteristics in rock joints under high normal load and strong confinement is essential for ensuring the safety of deep engineering construction and mitigating geological disasters.This study conducted shear experiments on rough rock joints under displacement-controlled dynamic normal loads,investigating the shear behaviors of joints across varying initial normal loads,normal loading frequencies,and normal loading amplitudes.Experimental results showed that the peak/valley shear force values increased with initial normal loads and normal loading frequencies but showed an initial increase followed by a decrease with normal loading amplitudes.Dynamic normal loading can either increase or decrease shear strength,while this study demonstrates that higher frequencies lead to enhanced friction.Increased initial normal loading and normal loading frequency result in a gradual decrease in joint roughness coefficient(JRC)values of joint surfaces after shearing.Positive correlations existed between frictional energy dissipation and peak shear forces,while post-shear joint surface roughness exhibited a negative correlation with peak shear forces through linear regression analysis.This study contributes to a better understanding of the sliding responses and shear mechanical characteristics of rock joints under dynamic disturbances.展开更多
First we calibrated the spectrometer in atmosphere using the peak-channel of 241Am, Thc-c' standard radioactive source while the window diameter isφ3. 0 mm and gained following formula with respect to the energy ...First we calibrated the spectrometer in atmosphere using the peak-channel of 241Am, Thc-c' standard radioactive source while the window diameter isφ3. 0 mm and gained following formula with respect to the energy (E/MeV) ofαand the channel (Ch): E=1. 507 55 + 0. 016 31×Ch+6. 235 24×10-6×Ch2 So, when E=5. 486 MeV, the Ch is equal to 221. 493. When changing the diameter of incident window toφ1.5 mm, we find the peak-channel of展开更多
基金Projects(52174092,51904290)supported by the National Natural Science Foundation,ChinaProject(BK20220157)supported by the Natural Science Foundation of Jiangsu Province,China+1 种基金Project(232102321009)supported by Henan Province Science and Technology Key Project,ChinaProject(2022YCPY0202)supported by Fundamental Research Funds for the Central Universities,China。
文摘A comprehensive understanding of the dynamic frictional characteristics in rock joints under high normal load and strong confinement is essential for ensuring the safety of deep engineering construction and mitigating geological disasters.This study conducted shear experiments on rough rock joints under displacement-controlled dynamic normal loads,investigating the shear behaviors of joints across varying initial normal loads,normal loading frequencies,and normal loading amplitudes.Experimental results showed that the peak/valley shear force values increased with initial normal loads and normal loading frequencies but showed an initial increase followed by a decrease with normal loading amplitudes.Dynamic normal loading can either increase or decrease shear strength,while this study demonstrates that higher frequencies lead to enhanced friction.Increased initial normal loading and normal loading frequency result in a gradual decrease in joint roughness coefficient(JRC)values of joint surfaces after shearing.Positive correlations existed between frictional energy dissipation and peak shear forces,while post-shear joint surface roughness exhibited a negative correlation with peak shear forces through linear regression analysis.This study contributes to a better understanding of the sliding responses and shear mechanical characteristics of rock joints under dynamic disturbances.
文摘First we calibrated the spectrometer in atmosphere using the peak-channel of 241Am, Thc-c' standard radioactive source while the window diameter isφ3. 0 mm and gained following formula with respect to the energy (E/MeV) ofαand the channel (Ch): E=1. 507 55 + 0. 016 31×Ch+6. 235 24×10-6×Ch2 So, when E=5. 486 MeV, the Ch is equal to 221. 493. When changing the diameter of incident window toφ1.5 mm, we find the peak-channel of