连续级配胶结充填体力学特性及声发射特征

Mechanical properties and acoustic emission characteristics of continuous graded cemented backfill

基于程潮铁矿尾砂胶结充填背景,配制7组不同Talbol指数n的连续级配胶结充填体试样,开展了单轴压缩胶结充填体声发射(AE)监测试验,获取了胶结充填体强度及声发射特征参数.研究结果表明:连续级配胶结充填体的强度随n的增大呈震荡上升,达到最大值后骤然下降,当n=0.5时,连续级配胶结充填体强度最优,连续级配胶结充填体试样破坏后表壁以主裂纹为主,主裂纹发育完整,属于单一裂纹贯穿破坏,当n≠0.5时,主裂纹沿扩展方向发生偏转,属于裂纹绕行扩展破坏;当n=0.5时,声发射能率与累积能量均呈现出明显与全应力应变曲线对应的阶段性变化特征,当n≠0.5时,声发射能率呈现周期性间断峰值变化规律,累积能量表现为明显的阶梯性变化特征.

Based on the background of tailings cemented backfill in Chengchao Iron Mine,seven groups of continuous cemented backfill samples with different Talbol index n were prepared,and the acoustic emission(AE) monitoring test of cemented backfill under uniaxial compression was carried out.The strength and AE characteristic parameters of cemented filling were obtained.The results show that the strength of continuous graded cemented backfill oscillates with the increase of n,reaches the maximum value,and then drops abruptly.When n=0.5,continuous gradation cemented packing has the best strength.The main cracks are found on the surface after the failure of continuous graded cemented backfill samples. The main crack is fully developed and belongs to single crack penetration failure.When n≠0.5,the main crack deflects along the propagation direction and belongs to crack detour propagation failure. When n=0.5, both AE energy rate and accumulated energy show a characteristic of phased changes corresponding to the total stress-strain curve.When n≠0.5,the AE energy rate presents a rule of periodic intermittent peak change,and accumulated energy shows an obvious step-change characteristic.