调控层胶结充填体三轴压缩力学性能及破坏特征研究  

Mechanical properties and failure characteristics of strengthening stratified cemented tailings backfill under triaxial compression

作　　者：徐文彬[1] 赵康奇 张亚伦 刘成保 周磊 XU Wen-bin;ZHAO Kang-qi;ZHANG Ya-lun;LIU Cheng-bao;ZHOU Lei(School of Energy and Mining Engineering,China University of Mining&Technology(Beijing),Beijing 100083,China;Anhui Masteel Mining Resources Group Co.,Ltd.,Maanshan,Anhui 243000,China)

机构地区：[1]中国矿业大学(北京)能源与矿业学院,北京100083 [2]安徽马钢矿业资源集团有限公司,安徽马鞍山243000

出　　处：《岩土力学》2024年第12期3658-3667,3680,共11页Rock and Soil Mechanics

基　　金：中央高校基本业务费(No.2023JCCXNY01);重点研发计划项目(No.2022AB31022)。

摘　　要：为了解决阶段空场嗣后充填法二步骤矿柱开采时一步骤采场充填体易失稳垮塌的难题,提出了充填调控层理念,以增强一步骤采场充填体的稳定性。借助三轴压缩试验仪,分析了不同调控层高度、主体层灰砂比和围压对充填体力学性能及破坏规律的影响,探究了单层充填体与含调控层充填体偏应力-应变曲线特征及破坏模式的差异性。结果表明:调控层强化了充填体的屈服阶段,进而提高了其峰值强度;调控层占比不变时,主体层灰砂比越小,强化效果越好;主体层灰砂比不变时,调控层占比越大,强化效果越好;围压与充填体峰值强度呈对数函数关系,表观黏聚力c、表观内摩擦角φ值与充填体的主体层灰砂比、调控层占比大小呈线性相关;未添加调控层充填体的破坏形式以斜剪切裂纹为主,添加调控层后则以剪切、拉伸以及混合破坏3种形式为主;调控层占比不变,主体层灰砂比较小时,拉伸裂纹贯穿调控层;验证了含调控层充填体配比1:20-2/5(表示充填体的主体层灰砂比为1:20,调控层占比为整体的2/5)替代某矿原充填体配比(1:7-0)的可行性,1:20-2/5单位体积充填体可节约6.85%水泥用量。研究结果可为节约矿山充填成本和提高作业安全提供一定的理论指导。In order to solve the collapsible difficulties of primary stope in subsequent stoping backfilling method,the idea of strengthening stratified structure in primary stoping backfill is put forward.The effect of strengthening stratified height,cement-to-tailings ratio and confining pressure on the mechanical properties and failure rules of cemented tailings backfill(CTB)is investigated by the triaxial compressive testing.The difference of deviational-stress-strain curves and failure modes between CTB and strengthening stratified CTB is investigated.The results show that the yield phase and peak strength of CTB are enhanced by the strengthening stratified structure in CTB.When the strengthening stratified thickness keeps constant,the strengthening effect is raised as the cement-to-tailings ratio in the main layer become lower.Moreover,the cement-to-tailings ratio in the main layer remains unchanged,the strengthening effect is advanced by the increase of strengthening stratified thickness as well.The peak strength of CTB is logarithmically increased with confining pressures,and the apparent cohesion and friction angle are linearly increased with cement-to-tailings ratio in the main layer and strengthening stratified thickness.The failure mode of CTB without strengthening stratified structure is mainly dominated by an oblique shear crack,and the strengthening stratified CTB presents three failure modes:shear,tensile and mixed.When the cement-to-tailings ratio in the main layer is low,tensile cracks run through the strengthening stratified structure.The feasibility of 1:7−0 backfill replaced by 1:20−2/5 is verified,and the backfill cost of 1:20−2/5 can be saved by 6.85%cement cost,where 1:20 is cement-to-tailings ratio,and 2/5 is the proportion of strengthening stratified.The results can provide theoretical references for saving backfill cost and improving operation safety.

关 键 词：调控层 胶结充填体 力学性能 应力-应变曲线 破坏模式 

分 类 号：TU457[建筑科学—岩土工程]