The rockburst caused by underground engineering excavation exhibits a significant lag effect.Studies have shown that the occurrence of lag-type rockburst is closely related to the delayed failure of rocks.This paper f...The rockburst caused by underground engineering excavation exhibits a significant lag effect.Studies have shown that the occurrence of lag-type rockburst is closely related to the delayed failure of rocks.This paper focuses on the delayed failure characteristics of unloading-damaged sandstone under the combined action of static load and dynamic disturbance.Numerical simulations are utilized to analyze the delayed failure evolution characteristics and failure mechanisms of sandstone.The results indicate that in triaxial unloading delay failure tests,the duration of loading decreases exponentially with the increase of initial unloading damage.Compared to static load conditions,the duration of loading under dynamic disturbance decreases by more than 43%,and the average strain rate significantly increases.The number of cracks at the endpoint of triaxial unloading delay failure increases as initial unloading damage decreases,with a substantial increase in the number of cracks under dynamic disturbance.These findings provide a valuable reference for the timeliness and delayed rockburst analysis and interpretation of rock damage and failure under high-stress levels.展开更多
基金the financial support provided by the National Natural Science Foundation of China(Grant No.U22A20600,U2034203).
文摘The rockburst caused by underground engineering excavation exhibits a significant lag effect.Studies have shown that the occurrence of lag-type rockburst is closely related to the delayed failure of rocks.This paper focuses on the delayed failure characteristics of unloading-damaged sandstone under the combined action of static load and dynamic disturbance.Numerical simulations are utilized to analyze the delayed failure evolution characteristics and failure mechanisms of sandstone.The results indicate that in triaxial unloading delay failure tests,the duration of loading decreases exponentially with the increase of initial unloading damage.Compared to static load conditions,the duration of loading under dynamic disturbance decreases by more than 43%,and the average strain rate significantly increases.The number of cracks at the endpoint of triaxial unloading delay failure increases as initial unloading damage decreases,with a substantial increase in the number of cracks under dynamic disturbance.These findings provide a valuable reference for the timeliness and delayed rockburst analysis and interpretation of rock damage and failure under high-stress levels.
