不同配比全尾砂胶结充填体的动态损伤特性

为得到不同配比下某铜矿尾砂胶结充填体的动力学特性及损伤度,对灰砂比分别为1∶4、1∶6、1∶8和1∶10,质量浓度为72%的充填体试件开展了相似加载应变率下的常规单轴冲击试验。结果表明:1)加载应变率为30s^-1,灰砂比为1∶4和1∶6的试件内部胶结力较强,受到冲击荷载后残余强度较高,仅在边缘处出现少量层状剥落,相同条件下灰砂比为1∶8、1∶10的试件破坏后多以粉质与劈裂柱状体的形式存在,基本丧失原有强度。2)灰砂比为1∶4、1∶6、1∶8和1∶10所对应的损伤值d分别为0.238、0.258、0.443和0.476,当灰砂比由1∶6变化为1∶8时,损伤变量值增幅达171.71%,此阶段充填体整体力学性质大幅度降低,动态抗压强度降低,动弹模量减小,但破坏应变增加,充填体变形性能趋向于脆性。

Dynamic Damage Characteristics of Cementing Backfill With Different Ratio of Tailing

In order to obtain the dynamic characteristics and damage degree of a copper mine tailings cemented backfill with different ratios, conventional uniaxial impact tests under similar loading strain rates were carried out on backfill specimens with 1:4, 1:6, 1:8 and 1:10 mass concentrations, respectively.Experimental results show that: (1) when the loading strain rate for 30 s - 1, contrast ratio of 1:4 and 1:6 specimen internal cementation force strong, high residual strength after impact load, in only the edges appear a small amount of layered peeling, contrast in the same conditions as 1:8, 1:10 specimen after damage to more opaque and splitting the plume in the form of basic loss of its original strength;(2) the contrast ratio of 1:4, 1:6, 1:8 and 1:10 the damage value of the corresponding d 0.238, 0.258, 0.443 and 0.476, respectively, when the contrast by 1:6 change for 1:8, damage variable value increased by 171.71%, the overall mechanical properties greatly reduced, this stage filling body dynamic compressive strength is reduced, moving die is reduced, but the failure strain increases, the filling body deformation properties tend to be brittle.