矿山嗣后充填法中,采用经验类比法判定胶结充填体的强度存在诸多问题。利用新的方法来分析充填体与岩体的匹配是必要的。对某铜矿灰砂比为1∶6、1∶8、1∶10和1∶12的4种尾砂胶结充填体进行力学试验和匹配分析。首先利用损伤力学方法建立充填体破坏前本构方程,根据岩体开挖释放能量与充填体蓄积应变能相近的原则,来判定岩体与充填体的匹配;然后运用GTS/MI-DAS有限元软件模拟开采-充填过程,根据应力变化与充填体极限强度的大小关系判定两者的匹配。2种方法所得到的结论一致。分析结果表明,该矿山宜采用充填配比不小于1∶10的尾砂胶结充填体。
Since some problems occur when adopting experience analogy method to determine the filling strength in the underground stope after mining excavation,it is necessary to use a new method to evaluate strength match between backfill and rock mass.The strength of four types of backfill in a copper mine with different cement-tailing ratios of 0.167,0.125,0.100 and 0.083 were tested in laboratory.First,the damage constitutive equations were investigated based on damage mechanics.According to the principle that releasing energy from excavated rock mass should correspond to the cumulative strain energy in backfill,a reasonable match between backfill and rock mass was discussed.Second,the process of mining and filling was simulated by GTS/MIDAS.Based on the size relation of secondary stress and the strength of backfill,feasible backfill were gained.The numerical simulation was used to validate the theoretical analysis results.The results of the two methods are consistent.The backfill with cement-tailing ratios of 0.167,0.125 and 0.100 can be used in the mine.