不同灰砂比尾砂胶结充填材料组合体力学特性及协同变形研究

Mechanical properties and synergistic deformation characteristics of tailings cemented filling assembled material body with different cement-tailings ratios

为研究不同灰砂比尾砂胶结充填材料组合体力学特性及协同变形特征,采用单轴压缩试验对2种不同灰砂比组合体开展相关研究。试验结果表明:(1)组合体的整体峰值强度取决于灰砂比较小试件的峰值强度,但当灰砂比较小试件的峰值强度接近于灰砂比较大试件的比例极限强度时,组合体的整体峰值强度相比灰砂比较小试件的峰值强度降低了29.22%;2个试件峰值强度比越小,组合体的整体弹性模量越大;随着组合体中两试件峰值强度比的增大,组合体中灰砂比较大试件的泊松比越小,灰砂比较小试件的泊松比却越大。(2)组合充填体的应力‐应变曲线与峰值强度较小试件的曲线在数值和变化趋势上相似,其破坏主要为贯穿灰砂比较小试件的剪切和张拉破坏,组合体中两试件破坏变形虽在时间上表现出一定的滞后性,但其协同变形特征较明显;(3)不同灰砂比组合体的声发射在4个阶段有着不同的活动特征,且其应力峰值滞后于声发射振铃计数峰值,组合体中灰砂比较大试件的振铃计数峰值分别占其对应灰砂比较小试件的13.77%,14.16%和6.56%,随着组合体强度比的增大,组合体的声发射振铃计数整体减少。

In order to study the mechanical properties and synergistic deformation characteristics of the tailings cemented filling material assembled with various cement-tailings ratios,the uniaxial compression test was used to study two different cement-tailings ratios assemblies.Experimental results show that:(1)the overall peak strength of assembled material body depends on the peak strength of the small cement-tailings ratio specimen.When the peak strength of the small cement-tailings ratio specimen is close to the proportional ultimate strength of the large cement-tailings ratio specimen,the overall peak strength of the assembled material body is reduced by 29.22%.The smaller the peak strength ratio of the two specimens is,the larger the overall elastic modulus of the assembled body.The Poisson¢s ratio of the specimen with a large cement-tailings ratio becomes smaller,while becomes larger with a mall cement-tailings ratio,with the peak strength ratio of the two specimens in assembled body.(2)The stress-strain curve of the assembled backfill body is similar to the curve of the specimen with a smaller peak strength in terms of value and change trend.The failure mode is mainly manifested as the shear failure and tension failure penetrated in the specimen with a small cement-tailings ratio.Although the failure deformation of two specimens in the assembled body shows a certain hysteresis in time,its synergistic deformation characteristics are obvious.(3)The acoustic emission of the assembled body with different cement-tailings ratios has different activity characteristics in the four stages and the stress peak lags behind the peak of acoustic emission ringing count.The count peaks of the large cement-tailings ration specimens in the assembled body account for 13.77%,14.16%and 6.56%of the corresponding small cement-tailings ratio ones.As the strength ratio of the assembled body increasing,the acoustic emission ringing count of the combination decreases gradually.