In mining engineering,dynamic loads acting on the surrounding rock induce irreversible damage.The damage is further exacerbated by water exudation from filling bodies or groundwater in the surrounding rock.Understandi...In mining engineering,dynamic loads acting on the surrounding rock induce irreversible damage.The damage is further exacerbated by water exudation from filling bodies or groundwater in the surrounding rock.Understanding the propagation and energy characteristics of stress waves in damaged surrounding rock is essential for improving the stability of underground structures.Hence,in this study,an improved triaxial Split Hopkinson Pressure Bar(SHPB)testing system was used to prepare four sets of impact-damaged and water-soaked specimens with varying length-to-diameter ratios in the laboratory,followed by dynamic triaxial compression testing.Test results indicate that,following dynamic impact and water soaking,the propagation of stress waves in rock is altered.Compared with intact specimens,impact-damaged and water-soaked specimens(IDWS)show a reduction in both transmission and reflection coefficients,thereby enhancing their energy absorption capacity and decreasing transmitted and reflected energy.The length(length-to-diameter ratio)of the specimen and the peak of the incident wave also affect stress wave propagation.Under the same incident peak value,the transmission coefficient increases with larger length-to-diameter ratios,whereas the reflection coefficient decreases.Similarly,the energy carried by the stress wave is influenced by specimen length:as the length grows,the energy absorbed per unit volume declines.When using energy absorbed per unit volume to characterize the dynamic triaxial strength of rock,the length-to-diameter ratio effect on strength is not pronounced.展开更多
基金funded by the National Key Research and Development Program of China-2023 Key Special Project(Grant No.2023YFC2907400)the Hunan Provincial Natural Science Foundation for Distinguished Young Scholars(Grant No.2023JJ10072)the Science and Technology Innovation Program of Hunan Province(Grant No.2022RC1173).
文摘In mining engineering,dynamic loads acting on the surrounding rock induce irreversible damage.The damage is further exacerbated by water exudation from filling bodies or groundwater in the surrounding rock.Understanding the propagation and energy characteristics of stress waves in damaged surrounding rock is essential for improving the stability of underground structures.Hence,in this study,an improved triaxial Split Hopkinson Pressure Bar(SHPB)testing system was used to prepare four sets of impact-damaged and water-soaked specimens with varying length-to-diameter ratios in the laboratory,followed by dynamic triaxial compression testing.Test results indicate that,following dynamic impact and water soaking,the propagation of stress waves in rock is altered.Compared with intact specimens,impact-damaged and water-soaked specimens(IDWS)show a reduction in both transmission and reflection coefficients,thereby enhancing their energy absorption capacity and decreasing transmitted and reflected energy.The length(length-to-diameter ratio)of the specimen and the peak of the incident wave also affect stress wave propagation.Under the same incident peak value,the transmission coefficient increases with larger length-to-diameter ratios,whereas the reflection coefficient decreases.Similarly,the energy carried by the stress wave is influenced by specimen length:as the length grows,the energy absorbed per unit volume declines.When using energy absorbed per unit volume to characterize the dynamic triaxial strength of rock,the length-to-diameter ratio effect on strength is not pronounced.
