基于细观尺度的胶结充填体破坏模拟试验研究

Simulation Research on Cemented Tailings Backfill Damage Based on Microscopic Scale

为分析充填体材料细观裂纹的萌生、扩展以及相互贯通的破坏机制,从尾砂胶结充填体微细观结构出发,采用Weibull统计函数对充填体材料的非均质特性进行描述,结合充填体室内力学试验结果,建立基于有限元理论的RFPA2D数值力学模型,分析胶结充填体的细观破坏演化模式和声发射特性。研究结果表明:尾砂胶结充填体是一种多相复合材料,具有强度低、非均质性高等特点;试件的破坏首先发生于力学性质较为薄弱的部位,并以此经过微-细-宏观跨尺度发展,最终导致充填体破坏;充填体破裂过程的声发射演化规律反映了裂纹发展的动态特征。

In order to analyze issues of initiation, development and interconnection of filling materialcrack, the weibull statistical functions were adopted in describing heterogeneous backfill materialfrom the cemented tailings backfill mesoscopic structures. The research of backfill damage mechanismswas carried out by using RFPA20 numerical simulation software combined with the backfillmechanical test results. The meso damage evolution model and acoustic emission characteristics ofcemented tailings backfill were analyzed. The results showed that cemented tailings backfill was amulti - phase composite material. The cemented tailings backfill was of low intensity and high heterogeneity.Specimen damage firstly occured in the relatively weak position, then grew through themicro - fine - macro cross - scale development, and finally lead to the destruction of backfill. Acousticemission evolution of filling rupture process reflected the dynamic characteristics of crackgrowth.