饱和度影响下胶结充填体三轴力学特性试验研究  

Experimental study on the effect of saturation on the triaxial mechanical properties of cemented tailings backfill

作　　者：吴蔚律 徐文彬[1] WU Weilü;XU Wenbin(School of Energy and Mining Engineering,China University of Mining&Technology(Beijing),Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)能源与矿业学院,北京100083

出　　处：《中南大学学报（自然科学版）》2023年第10期4015-4029,共15页Journal of Central South University:Science and Technology

基　　金：重点研发计划项目(2018YFE0123000);中央高校基本科研业务费专项资金资助项目(2023JCCXNY01)。

摘　　要：井下环境温度和湿度与室内标准养护条件下的不同,导致充填体原位强度和室内试验强度差异显著。为揭示养护龄期和含水饱和度对胶结充填体-水特征曲线及其力学性能的影响,分别借助三轴固结不排水压缩试验和充填体-水特征曲线测试方法,分析不同养护龄期与饱和度下充填体的三轴压缩变形特征参数和基质吸力变化规律。研究结果表明:养护龄期越长,充填体内部孔隙结构越致密,脱水越困难,相同饱和度下充填体内部的基质吸力越高;相同养护龄期下,充填体的饱和度越低,基质吸力越高;饱和充填体的变形特征与其内部结构强度相关,而非饱和充填体的变形特征主要受基质吸力影响,基质吸力与弹性模量呈正相关,与泊松比呈负相关;随着饱和度降低,充填体强度先小幅下降后上升。Underground in-situ strength of cemented tailings backfill(CTB)is significantly different from that of the laboratory curing sample,which is mainly caused by different temperature and humidity environment between underground and standard curing.In order to reveal the influence of curing age and water saturation on the CTB-water characteristic curve and mechanical properties of cemented backfill,the triaxial compression deformation characteristic parameters and the variation rule of matrix suction of backfill at different curing ages and saturation were analyzed by means of triaxial consolidation undrained compression test and CTB-water characteristic curve test.The results show that the longer the curing age,the denser the pore structure inside the CTB;the more difficult the dehydration,the higher the matric suction inside the backfill at the same saturation.The lower the saturation of the CTB,the higher the matric suction at the same curing age.The deformation characteristics of saturated CTB are related to internal structural strength,while the deformation characteristics of unsaturated backfill are mainly affected by matric suction,which is positively correlated with elastic modulus and negatively correlated with Poisson's ratio.With the decrease of saturation,the strength of CTB decreases slightly at first and then increases.

关 键 词：胶结充填体 饱和度 基质吸力 泊松比 孔隙结构 

分 类 号：TD853[矿业工程—金属矿开采]