Effect of early damage of tailings cemented backfill on later mechanical properties

GAN Deqing; ZHANG Yajie; LIU Zhiyi; LU Yanze

doi:10.16186/j.cnki.1673-9787.2021120073

Abstract：Objectives To explore the impact of early damage to cemented tailings backfill on its later bearing performance.Methods Uniaxial compression tests were conducted on early-damaged backfill after a certain age of maintenance.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 the later mechanical properties.The influence of the damage age and degree on the later mechanical properties of the filling body was analyzed.Results The results show that:at the same damage age,the late peak stress and residual stress of the backfill are the lowest at 80%compression loss;the degree of damage has less influence on the late deformation characteristics of the backfill with the age of 3 d and 7 d,and has a greater weakening effect on the late deformation characteristics of the backfill with the age of 14 d and 21 d;the degree of damage below 80%has less 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 14 d and 21 d 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 in-creases with the increase in the degree of compression damage.The damage to the filling body after 14 d of main-tenance has a significant impact on its later mechanical properties,and the degree of damage has a significant impact on the later mechanical properties of backfill after 14 d of maintenance.Conclusions The research re-sults can provide theoretical guidance for filling quality control in upward horizontal filling mining methods.