工程科学学报.第42卷.第10期:1286-1298.2020年10月 Chinese Journal of Engineering,Vol.42,No.10:1286-1298,October 2020 https://doi.org/10.13374/j.issn2095-9389.2019.12.29.003;http://cje.ustb.edu.cn 分层胶结充填体力学特性及裂纹演化规律 唐亚男,2),付建新1,2)区,宋卫东12),张永芳12) 1)北京科技大学土木与资源工程学院,北京1000832)北京科技大学金属矿山高效开采与安全教育部重点实验室,北京100083 通信作者.E-mail:fujune0011@126.com 摘要在进行大尺寸采空区嗣后充填过程中,胶结充填体易出现分层等结构现象.为深人分析结构特征对胶结充填体力学 特性及裂纹演化规律的影响,首先制作中间层高度比为0.2、0.4、0.6和0.8,灰砂比为1:4、1:6、1:8和1:10的分层胶结 充填体试件,然后利用GAW-2000伺服试验系统开展单轴压缩试验,最后借助二维颗粒流软件(PFC-2D),分析胶结充填体 内部裂纹分布规律.结果表明:(1)分层充填体单轴抗压强度与高度比呈指数函数关系、与灰砂比呈多项式函数关系:弹性模 量与高度比及灰砂比均呈多项式函数关系:单轴抗压强度及弹性模量均随高度比的增加而减小、随灰砂比的增大而增大,且 两者对灰砂比敏感度更高.(2)充填体内部裂纹演化曲线先缓慢上升,达到单轴抗压强度的80%左右时快速上升.且灰砂比 越大、高度比越大,上升速度越快,拐点到来越早,充填体试件越易发生破坏,超过单轴抗压强度后曲线开始迅速下降。(3)分 层充填体主要表现为剪切破坏、张拉破坏及共轭剪切破坏,且破坏主要集中于中间软弱层:高度比越大,试件内部裂纹越密 集,灰砂比越大,裂纹越易向两端演化. 关键词阶段嗣后充填:分层胶结充填体:单轴抗压强度:裂纹演化规律 分类号TD853 Mechanical properties and crack evolution of interbedded cemented tailings backfill TANG Ya-nan2),FU Jian-xin2,SONG Wei-dong2,ZHANG Yong-fang2) 1)School of Civil and Resources Engineering,University of Science and Technology Beijing,Beijing 100083,China 2)Key Laboratory of High-Efficient Mining and Safety of Metal Mines,Ministry of Education,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:fujun0011@126.com ABSTRACI In the process of filling a large-scale goaf,due to the limitations in the capacity of the mixing tank,it is difficult to completely filling the goaf all once,but multiple fillings of a goaf can easily produce a layered structure in the cemented tailings backfill. This layered structure has a significant effect on the mechanical properties of the cemented tailings backfill.To analyze the influence of these structural characteristics on the mechanical properties and evolution of cracks in cemented tailings backfill,the layered cemented tailings backfill specimens with height ratios of 0.2,0.4,0.6 and 0.8,and cement-tailing ratios of 1:4,1:6,1:8 and 1:10 were made,and then the uniaxial compression test was carried out by using a GAW-2000 servo test system,and finally the crack distribution inside the cemented tailings backfill were analyzed by using 2D particle flow software(PFC-2D).The results show that:(1)the relationship between the uniaxial compressive strength and the height ratio of the layered backfill can be represented by an exponential function,and the relationship between the uniaxial compressive strength and the cement-tailing ratio can be represented by a polynomial function.The relationship between the elastic modulus and the height ratio and the cement-tailing ratio can be represented by a polynomial function.The uniaxial compressive strength and the elastic modulus are found to decrease with increase in the height ratio, and increase with increase in the cement-tailing ratio,with both being more sensitive to the cement-tailing ratio.(2)The evolution curve 收稿日期:2019-12-29 基金项目:国家自然科学基金资助项目(51804016):中央高校基本科研业务费资助项目(FRF-TP19-014A3)分层胶结充填体力学特性及裂纹演化规律 唐亚男1,2),付建新1,2) 苣,宋卫东1,2),张永芳1,2) 1) 北京科技大学土木与资源工程学院,北京 100083 2) 北京科技大学金属矿山高效开采与安全教育部重点实验室,北京 100083 苣通信作者,E-mail:fujun0011@126.com 摘 要 在进行大尺寸采空区嗣后充填过程中,胶结充填体易出现分层等结构现象. 为深入分析结构特征对胶结充填体力学 特性及裂纹演化规律的影响,首先制作中间层高度比为 0.2、0.4、0.6 和 0.8,灰砂比为 1∶4、1∶6、1∶8 和 1∶10 的分层胶结 充填体试件,然后利用 GAW–2000 伺服试验系统开展单轴压缩试验,最后借助二维颗粒流软件(PFC–2D),分析胶结充填体 内部裂纹分布规律. 结果表明:(1)分层充填体单轴抗压强度与高度比呈指数函数关系、与灰砂比呈多项式函数关系;弹性模 量与高度比及灰砂比均呈多项式函数关系;单轴抗压强度及弹性模量均随高度比的增加而减小、随灰砂比的增大而增大,且 两者对灰砂比敏感度更高. (2)充填体内部裂纹演化曲线先缓慢上升,达到单轴抗压强度的 80% 左右时快速上升,且灰砂比 越大、高度比越大,上升速度越快,拐点到来越早,充填体试件越易发生破坏,超过单轴抗压强度后曲线开始迅速下降. (3)分 层充填体主要表现为剪切破坏、张拉破坏及共轭剪切破坏,且破坏主要集中于中间软弱层;高度比越大,试件内部裂纹越密 集,灰砂比越大,裂纹越易向两端演化. 关键词 阶段嗣后充填;分层胶结充填体;单轴抗压强度;裂纹演化规律 分类号 TD853 Mechanical properties and crack evolution of interbedded cemented tailings backfill TANG Ya-nan1,2) ,FU Jian-xin1,2) 苣 ,SONG Wei-dong1,2) ,ZHANG Yong-fang1,2) 1) School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China 2) Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, University of Science and Technology Beijing, Beijing 100083, China 苣 Corresponding author, E-mail: fujun0011@126.com ABSTRACT In the process of filling a large-scale goaf, due to the limitations in the capacity of the mixing tank, it is difficult to completely filling the goaf all once, but multiple fillings of a goaf can easily produce a layered structure in the cemented tailings backfill. This layered structure has a significant effect on the mechanical properties of the cemented tailings backfill. To analyze the influence of these structural characteristics on the mechanical properties and evolution of cracks in cemented tailings backfill, the layered cemented tailings backfill specimens with height ratios of 0.2, 0.4, 0.6 and 0.8, and cement-tailing ratios of 1∶4, 1∶6, 1∶8 and 1∶10 were made, and then the uniaxial compression test was carried out by using a GAW–2000 servo test system, and finally the crack distribution inside the cemented tailings backfill were analyzed by using 2D particle flow software(PFC-2D). The results show that: (1) the relationship between the uniaxial compressive strength and the height ratio of the layered backfill can be represented by an exponential function, and the relationship between the uniaxial compressive strength and the cement-tailing ratio can be represented by a polynomial function. The relationship between the elastic modulus and the height ratio and the cement-tailing ratio can be represented by a polynomial function. The uniaxial compressive strength and the elastic modulus are found to decrease with increase in the height ratio, and increase with increase in the cement-tailing ratio, with both being more sensitive to the cement-tailing ratio. (2) The evolution curve 收稿日期: 2019−12−29 基金项目: 国家自然科学基金资助项目(51804016);中央高校基本科研业务费资助项目(FRF-TP-19-014A3) 工程科学学报,第 42 卷,第 10 期:1286−1298,2020 年 10 月 Chinese Journal of Engineering, Vol. 42, No. 10: 1286−1298, October 2020 https://doi.org/10.13374/j.issn2095-9389.2019.12.29.003; http://cje.ustb.edu.cn