不同含量玻璃纤维尾砂充填体损伤规律与围岩匹配关系

Damage law of cemented tailings backfill with different contents of glass fiber and its match with rock mass

为提高三门峡罗山金矿采空区充填后的稳定性,对玻璃纤维质量含量分别为0%,0.5%和0.7%的尾砂胶结充填体损伤规律进行研究。通过单轴压缩试验得到不同含量玻璃纤维尾砂胶结充填体应力-应变曲线,并根据建立的损伤本构方程,分析充填体的能量耗散规律,得出其与围岩的匹配关系。研究结果表明:(1)在一定范围内,玻璃纤维的掺入提高了充填体的强度,降低了初始弹性模量。(2)掺入玻璃纤维能够降低充填体达到峰值应力时的损伤值,但随着其含量的增加,充填体损伤值达到极值的过程越缓慢。(3)得到了不同含量玻璃纤维充填体的峰值比能计算模型,进而得出充填体的峰值比能随着玻璃纤维含量的增加而增大。(4)以该矿山充填开采为背景,得到采空区埋深与充填体强度的匹配设计模型,可为矿山节约充填成本提供科学依据。

In order to improve the stability of mined-out areas after filling in a metal mine,the damage law of cemented tailings backfill with different contents(0%,0.5%and 0.7%)of glass fibers was studied.The stress-strain curves of cemented tailings backfill with different contents of glass fiber were obtained by uniaxial compression.The energy dissipation law of backfill was analyzed according to the damage constitutive equation,and its match with rock mass was obtained.The results show that:(1)in a certain range,the strength of backfill is improved with the addition of glass fiber but the elastic modulus is reduced.(2)The damage value of backfill when reaching the peak stress is reduced with adding glass fiber,but with the increase of its contents,the process of damage value reaching the maximum of backfill is slower.(3)The calculation model of peak specific energy of backfill with different contents of glass fiber is obtained,and the peak specific energy of backfill increases with the increase of contents of glass fiber.(4)Based on the filling mining of the mine,the design model of the depth of the goaf and the strength of the backfill is obtained,which can provide a scientific basis for saving the backfill cost of the mine.