doi:10.16186/j.cnki.1673-9787.2021120073

Received:2021-12-20

Revised:2022-05-31

Online Date: 2024-01-25

Effect of early damage of tailings cemented backfill on later mechanical properties（Online）

GAN Deqing1,2,3,4, ZHANG Yajie1,2,3,4, LIU Zhiyi1,2,3,4, LU Yanze5

1.School of Mining Engineering，North China University of Science and Technology，Tangshan  063210，China；2.Development and Safety Key Laboratory of Hebei Province，North China University of Science and Technology，Tangshan，Hebei  063210，Chin；3.3.Collaborative Innovation Center of Green Development and Ecological Restoration of Mineral Resources，North China University of Science and Technology，Tangshan，Hebei 063210.4.Mine Green Intelligent Mining Technology Innovation Center of Hebei Province，North China University of Science and Technology，Tangshan，Hebei  063210；4.Shahe Zhongguan Iron Ore Co.，Ltd.，Hebei Iron and Steel Group，Xingtai  054100，China

Abstract:  Objective To explore the impact of early damage to cemented tailings backfill on its later bearingperformance. Methods Uniaxial compression tests were conducted on early damaged backfill after a certain age ofmaintenance.The damage age and degree were used as variables，and the later deformation characteristics，compressive strength，and elastic modulus of the damaged filling body were used as evaluation indicators for thelater mechanical properties.The influence of the damage age and degree on the later mechanical properties of thefilling body was analyzed. Results The results show that: at the same damage age，the late peak stress and residualstress of the backfill at 80% compression loss are the lowest;the degree of damage has less influence on the latedeformation characteristics of the backfill with the age of 3 d and 7 d，and has a greater weakening effect on thelate deformation characteristics of the backfill with the age of 14 d and 21 d;the degree of damage below 80% hasless influence on the late compressive strength of the backfill with the age of 3 d and 7 d.Each degree of damage to the age of 14d and 21d filling body late compressive strength has a greater impact，the greater the degree of damage，the lower the late compressive strength;each age of the filling body late elastic modulus increases with the increase in the degree of compression damage.The damage to the filling body after 14 days of maintenance has a significant impact on its later mechanical properties，and the degree of damage has a significant impact onthe later mechanical properties of backfill after 14 days of maintenance. Conclusion The research results canprovide theoretical guidance for filling quality control in upward horizontal filling mining methods.

Key words:cemented backfill;early damage;stress-strain relationship;compressive strength;mechanical properties

CLC：TD853.343