单轴压缩胶结充填体声发射参数时空演化规律及破裂预测

Space-time evolution of acoustic emission parameters of cemented backfill and its fracture prediction under uniaxial compression

为了研究胶结充填体在荷载作用下的时空演化规律,利用WAW?300微机电液伺服万能试验系统与DS2系列全信息声发射监测系统,监测了胶结充填体试样在单轴压缩过程中的应力、应变变化规律和声发射活动,根据振铃计数率、能率的阶段性特征,将加载过程声发射参数变化规律分为3个阶段:上升期、平静期和活跃期,进而研究声发射参数时空演化规律;并利用振铃计数率、能率参数,结合尖点突变理论,进行胶结充填体破裂预测。研究表明:(1)单轴压缩条件下,胶结充填体属于延性破坏,裂纹贯穿属于剪切贯穿;(2)通过声发射参数演化规律及定位演化特征,分析得出胶结充填体在加载中是由局部破坏向整体失稳演化;(3)运用尖点突变理论进行胶结充填体破裂预测,并构建了破裂预测模型,预测结果与试验结果一致。研究结果可为人工矿柱稳定性监测和破裂预测提供依据。

In order to study the space-time evolution of cemented backfill under applied load,WAW-300 micro electromechanical servo universal test system and DS2 series full information acoustic emission monitoring system were used to monitor the stress, strain variation and acoustic emission activity of cemented backfill specimen during uniaxial compression.According to the stage characteristics of ringing count rate and energy rate,the variation law of acoustic emission parameters during loading the acoustic emission variation is divided into three stages:rising period,calm period and active period,and the space-time evolution law of acoustic emission parameters was further studied.The cemented backfill fracture was predicted using the ringing count rate and energy rate parameters,combined with cusp catastrophe theory.The research shows that:1) under uniaxial compression,the cemented backfill is ductile failure,and the crack penetration is shear penetration;2) during the loading process,the cemented backfill evolves from local failure to overall instability;3) the point mutation theory is used to predict the fracture of cemented backfill,and the fracture prediction model is proposed.The prediction results are consistent with the experimental results.The research results can provide a basis for the stability monitoring and fracture prediction of artificial pillars.