关键词: 充填开采, 胶结充填体, 霍普金森压杆试验, 爆破响应, LS-DYNA, 数值模拟

Abstract: Open-stope backfilling mining method is widely used in underground metal mining.The cemented tailing backfill not only bears the static load pressure，but also faces the blasting impact in the second-step mining process.Therefore，it is of great significance to investigate the dynamic characteristics and blasting response of cemented tailing backfill to ensure mining safety.Static and dynamic load tests were carried out through uniaxial compressive strength （UCS） and Split Hopkinson Pressure Bars （SHPB）.And ANSYS/LS-DYNA software was used to simulate the blasting response law of cemented tailing backfill in the second-step mining process.The study results show that:① dynamic compressive strength of consolidated backfill increases with the increase of strain rate，and they are approximately linear，the dynamic compressive strength is about twice of the static compressive strength under high strain conditions；② the thickness of the protective layer of backfill has a significant impact on the vibration speed and effective stress when blasting during second-step mining，the protective layer should be remained enough in the second-step mining progress，otherwise，the vibration speed of backfill and the effective stress of the backfill will be too large；③the initiation mode also has obvious influence on the blasting response of cemented tailing backfilling，as using hole-top initiation，the protective layer thickness should be 1.5 m，which can satisfy the cemented tailing backfill safety demand，however，for hole-bottom initiation， the protective layer thickness should be 1.8 m.The above study results is of certain reference significance to the design of the strength of cemented tailing backfill and the thickness of protective layer and initiation mode in second-step mining process.

Key words: Filling mining, Cemented tailing backfill, Split Hopkinson Pressure Bar （SHPB） test, Blasting response, LS-DYNA, Numerical simulation