基于声发射不同骨料含量胶结充填体损伤过程试验研究

Experimental study on damage process of cemented backfill with different aggregate contents based on acoustic emission

利用RMT-150C型岩石力学测试系统与PCI-2声发射仪,对纯尾砂、骨料质量分数20%及40%三种胶结充填体试样进行单轴压缩破坏声发射监测试验,研究了3种不同骨料含量胶结充填体力学特性以及基于累计声发射事件率的损伤演化特征。试验结果表明:含骨料试样破坏脆性特征更加明显,同时骨料含量的变化在一定程度上影响了胶结充填体承载损伤演化速度,对其承载能力有较大影响;纯尾砂试样与含40%骨料试样在峰值应力前不同阶段均出现不同幅度的声发射活跃现象,可作为矿山充填体声发射监测破坏预警的前兆信息;适量骨料的加入可起到提升充填性能的作用,但声发射事件率作为预警前兆信息则可能失效。

The uniaxial compressive and the AE monitoring tests were carried out on pure railings and three kinds of cemented backfill specimen with the aggregate contents of 20% and 40% u sing RMT-150C rock mechanics test system and PCI-2 acoustic e mission instrument to study the mechanical properties of cemen ted backfill with three different aggregate contents and the dam age evolution characteristics based on the cumulative acoustic e-mission event rate. The test results showed that the brittle characteristics of the specimen containing aggregate is more obvious and at the same time,the change of aggregate content affects the bearing damage evolution rate of cemented backfill to some ex tent. It has a great influence on its bearing capacity. Pure tailings specimens and specimens with the aggregate content of 40% be- fore the peak stress in different stages have different amplitude of AE active phenomenon,which can be used as the precursor infor matiou of acoustic emission monitoring and early warning of backfill in the mine. The addition of a proper amount of aggregate can improve the filling performance but the rate of acoustic emis sion event can＇t be used as early warning information.