A novel meta steel with negative Poisson’s ratio effect(termed as micro-NPR steel)is developed for rock support in deep underground engineering.It possesses high strength,high ductility,and high energy absorption cha...A novel meta steel with negative Poisson’s ratio effect(termed as micro-NPR steel)is developed for rock support in deep underground engineering.It possesses high strength,high ductility,and high energy absorption characteristics.In this paper,static tension and modified dynamic drop hammer tests are performed on this novel material to investigate its mechanical properties first.Then based on this material,a new generation of micro-NPR anchor cable is developed and applied in field tests subjected to blasting dynamic loads.The results of laboratory tests reveal that the ultimate elongation of micro-NPR steel under dynamic impacts is more than 30%and it is over 1.5 times that of Q235;the plastic and total energy absorption of micro-NPR are both significantly higher than that of Q235.Field test indicates the fine controlling effect of micro-NPR anchor cable on surrounding rock mass under dynamic loads.Axial force confirms that micro-NPR cables can distribute and absorb the dynamic energy uniformly around the supported rock when subjected to dynamic disturbance,avoiding local failure induced by excessive stress concentration.The excavation compensation principle and energy-absorbing characteristics are used to explain the support mechanisms.Thus,micro-NPR material and anchor cable can control and prevent dynamic disasters in deep underground engineering effectively.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41941018)the Foundation of State Key Laboratory for Geomechanics and Deep Underground Engineering(Grant No.SKLGDUEK 2217)the Collaborative Innovation Center for Prevention and Control of Mountain Geological Hazards of Zhejiang Province(Grant No.PCMGH-2022-03).
文摘A novel meta steel with negative Poisson’s ratio effect(termed as micro-NPR steel)is developed for rock support in deep underground engineering.It possesses high strength,high ductility,and high energy absorption characteristics.In this paper,static tension and modified dynamic drop hammer tests are performed on this novel material to investigate its mechanical properties first.Then based on this material,a new generation of micro-NPR anchor cable is developed and applied in field tests subjected to blasting dynamic loads.The results of laboratory tests reveal that the ultimate elongation of micro-NPR steel under dynamic impacts is more than 30%and it is over 1.5 times that of Q235;the plastic and total energy absorption of micro-NPR are both significantly higher than that of Q235.Field test indicates the fine controlling effect of micro-NPR anchor cable on surrounding rock mass under dynamic loads.Axial force confirms that micro-NPR cables can distribute and absorb the dynamic energy uniformly around the supported rock when subjected to dynamic disturbance,avoiding local failure induced by excessive stress concentration.The excavation compensation principle and energy-absorbing characteristics are used to explain the support mechanisms.Thus,micro-NPR material and anchor cable can control and prevent dynamic disasters in deep underground engineering effectively.
