Study on Tensile Strength Characteristics of Cemented Backfill with Full Tailings under Brazilian Splitting
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摘要:
研究充填体抗拉强度对维护采场稳定具有重大参考价值。充填体的破坏过程也是能量耗散的过程，养护龄期、分层数等因素直接影响充填体的强度大小及能量耗散。以全尾砂为骨料，制备一组质量浓度为78%，灰砂比分别为1∶4、1∶6、1∶8，养护龄期分别为3 d、7 d、14 d、28 d的胶结充填体进行巴西劈裂实验，分析了养护龄期与分层数对充填体强度、能量耗散及破坏规律的影响。结果表明：灰砂比一定时，不同分层的充填体的强度随养护龄期呈正相关关系；养护龄期一定时，强度与灰砂比呈正相关关系，分层会形成结构弱面，降低充填体强度。巴西劈裂过程中充填体的能量耗散随养护龄期的增长而增大，与强度变化特征一致；室内实验结果可以看出，充填体裂纹起裂点大多位于充填体中心点处，在破坏时主裂纹伴随无数微裂纹从中心点处开始萌生、扩展直至贯穿整个充填体，呈不规则形状向加载直径上扩散。不同分层充填体裂纹扩展较为连贯，部分充填体出现了分层界面局部错动的情况，断裂特征多为中心断裂与偏心断裂的复合式断裂。研究结果可为充填采矿设计、实际矿山充填提供理论支持。
Abstract:The failure process of backfill body is also a process of energy dissipation. Factors such as curing age and delamination number directly affect the strength and energy dissipation of the backfill body. In this paper, using whole tailings as aggregate, a group of cemented backfill with mass concentration of 78%, lime−sand ratio of 1∶4, 1∶6, 1∶8 and curing age of 3D, 7 d, 14 d and 28 d were prepared for Brazilian splitting experiment. The effects of mass concentration, curing age and delamination number on the strength, energy dissipation and failure law of the backfill body were analyzed. The results showed that when the cement−sand ratio was constant, the strength of the backfill body was positively correlated with the curing age, and when the curing age was fixed, the strength and the cement−sand ratio were positively correlated, and the delamination will form the weak surface of the structure and reduced the strength of the backfill body. In the Brazilian splitting process, the energy dissipation of the backfill body increases with the increased of curing age, which was consistent with the strength change characteristics; the crack initiation point of the backfill body was mostly located at the central point of the backfill body and spread into an irregular shape to the loading diameter. The indoor test results showed that the crack initiation point of the backfill body was mostly located at the central point of the backfill body, and during failure, the main crack started to initiate and propagated from the center point with numerous microcracks until it ran through the whole backfill body. It spread into an irregular shape to the loading diameter. The crack propagation of different layered backfill bodies was more coherent, and the local dislocation of the delamination interface occurs in some of the backfill bodies, most of the fracture characteristics were the compound fracture of central fracture and eccentric fracture.
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表 1 尾砂化学成分
Table 1. Chemical composition of tailings
成分 Cu As Ag S CaO MgO SiO2 Al2O3 Fe Bi K2O Ba 含量 0.14 0.55 6.7 4.59 3.01 2.30 19.10 3.27 22.02 0.005 1.24 11.02 注：除Ag含量单位为g/t外，余为%。 
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表 2 充填体抗拉强度结果
Table 2. Results of tensile strength of backfill body
分层数 灰砂比 不同养护龄期下的充填体抗拉强度/MPa 3 d 7 d 14 d 28 d Ⅰ 1∶4 0.130 0.384 0.505 0.577 1∶6 0.106 0.252 0.373 0.441 1∶8 0.051 0.177 0.228 0.278 Ⅱ 1∶4 0.123 0.310 0.403 0.508 1∶6 0.095 0.199 0.373 0.392 1∶8 0.037 0.142 0.228 0.238 Ⅲ 1∶4 0.118 0.226 0.351 0.443 1∶6 0.061 0.158 0.289 0.350 1∶8 0.025 0.132 0.158 0.216
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[1] SARI M, YILMAZ E, KASAP T, et al. Exploring the link between ultrasonic and strength behavior of cementitious mine backfill by considering pore structure[J]. Constr. Build. Mater., 2023, 370: 130588.
[2] SUN W, WANG H J, HOU K P. Control of waste rock−tailings paste backfill for active mining subsidence areas[J]. J. Clean. Prod., 2018, 171: 567−579. doi: 10.1016/j.jclepro.2017.9.253
[3] CAO H, GAO Q, ZHANG X Z, et al. Research progress and development direction of filling cementing materials for filling mining in iron mines of china[J]. Gels, 2022, 3: 192.
[4] SUN W, WU A X. HOU K P, et al. Real−time observation of meso−fracture process in backfill body during mine subsidence using X−ray CT under uniaxial compressive conditions[J]. Constr. Build. Mater., 2016, 113: 153–162.
[5] 侯永强, 尹升华, 曹永, 等. 单轴压缩下不同养护龄期尾砂胶结充填体损伤特性及能量耗散分析[J]. 中南大学学报(自然科学版), 2020, 51(7): 1955−1965.
HOU Y Q, YIN S H, CAO Y, et al. Damage characteristics and energy dissipation analysis of tailings cemented backfill at different curing ages under uniaxial compression[J]. Journal of Central South University (Natural Science Edition), 2020, 51(7): 1955−1965.
[6] GAO T, SUN W, LIU Z, et al. Investigation on fracture characteristics and failure pattern of inclined layered cemented tailings backfill[J]. Constr. Build. Mater., 2022, 343: 128110.
[7] TANG Y N, FU J X, SONG W D, et al. Mechanical properties and crack evolution of interbedded cemented tailings backfill[J]. Chinese J. Eng., 2020, 42: 1286−1298.
[8] WANG J, SONG W D, GAO S, et al. Mechanical properties and failure modes of stratified backfill under triaxial cyclic loading and unloading[J]. Int. J. Min. Sci. Technol., 2019, 29: 809−814.
[9] SUN W, GAO T, ZHAO J G, et. al. Research on fracture behavior and reinforcement mechanism of fiber−reinforced locally layered backfill: Experiments and models[J]. Constr. Build. Mater., 2023, 366: 130186.
[10] LIU X S, NING J G, Y. L. Tan, et al. Damage constitutive model based on energy dissipation for intact rock subjected to cyclic loading[J]. Int. J. Min. Sci. Technol., 2016, 85: 27−32.
[11] 刘志祥, 青灵, 党文刚. 尾砂胶结充填体损伤软−硬化本构模型[J]. 山东科技大学学报(自然科学版), 2012, 31(2): 36−41.
LIU Z X, LIU Q L, DANG W G. On softening−hardening intrinsically constitutive model for damage of tailings−cemented filling body[J]. Journal of Shandong University of Science and Technology (Natural Science), 2012, 31(2): 36−41.
[12] TAN Y L, GU Q H, NING J G, et al. Uniaxial compression behavior of cement mortar and its damage−constitutive model based on energy theory[J]. Materials, 2019: 1309. DOI: 10.3390/ma12081309.
[13] JIAO H Z, YANG W B, SHRN H M, et al. Study on multi−layer filling treatment of extra−large goaf and its underground application[J]. Materials, 2022, 16: 5680.
[14] SONG W D, WANG J, TAN Y Y, et al. Energy consumption and damage characteristics of layered filling under triaxial addition−unloading[J]. Int. J Min. Sci. Technol., 2017, 46(5): 1050−1057.
[15] HAN B, ZHANG S Y, SUN W. Impact of temperature on the strength development of the tailing−waste rock backfill of a gold Mine[J]. Adv. Civ. Eng. Mater. 2019, 43: 79606.
[16] SUN W, JIANG M G, FAN K, LIU Z. Determination and application of pressure loss in long distance pipeline transportation of paste slurry based on pipe loop experiment[J]. Arch. Min. Sci., 2022, 67: 223−237.
[17] LU K F, SUN W, GAO T, et al. Preparation of new copper smelting slag−based mine backfill material and investigation of its mechanical properties[J]. Constr. Build. Mater., 2023, 382: 131228.
[18] LI Z Y, SUN W, GAO T, et al. Experimental study on evolution of pore structure of inclined layered cemented tailings backfill based on X−ray CT[J]. Constr. Build. Mater., 2023, 366: 130242.
[19] GAO T, SUN W, LI Z Y, et al. Study on shear characteristics and failure mechanism of inclined layered backfill in mining solid waste utilization[J]. Minerals, 2022, 12(12): 1540.
[20] JIAO H Z, ZHANG W, YANG Y, et al. Static mechanical characteristics and meso−damage evolution characteristics of layered backfill under the condition of inclined interface[J]. Constr. Build. Mater., 2023, 366: 130113.
[21] 张辉, 程利兴, 苏承东, 等. 饱水煤样巴西劈裂强度和能量特征试验研究[J]. 中国安全生产科学技术, 2015, 11(12): 5−10.
ZHANG H, CHENG L X, SU C D, et al. Experimental study on Brazilian splitting strength and energy characteristics of saturated coal samples[J]. China Science and Technology of production Safety, 2015, 11(12): 5−10.
[22] 王辉, 李勇, 曹树刚, 等. 基于巴西劈裂实验的层状页岩断裂特征试验研究[J]. 采矿与安全工程学报, 2020, 37(3): 604−612.
WANG H, LI Y, Cao S G, et al. Experimental study on fracture characteristics of layered shale based on Brazilian splitting test[J]. Journal of Mining and Safety Engineering, 2020, 37(3): 604−612.
[23] TAN X, KONIETZKY H, FRÜ HWIRT T, et al. Brazilian tests on transversely isotropic rocks: laboratory testing and numerical simulations[J]. Rock Mechanics and Rock Engineering, 2015, 48(4): 1341−1351. doi: 10.1007/s00603-014-0629-2
[24] 肖福坤, 于涵, 侯志远, 等. 砂岩巴西劈裂破坏的位移场演化及能量耗散特征[J]. 黑龙江科技大学学报, 2018, 28(2): 125−129.
XIAO F K, YU H, HOU Z Y, et al. Displacement field evolution and energy dissipation characteristics of sandstone splitting failure in Brazil [J]. Journal of Heilongjiang University of Science and Technology, 2018, 28 (2): 125−129.
[25] 谢凯楠, 姜德义, 蒋翔, 等. 页岩巴西劈裂试验的能量分布与临界特征分析[J]. 煤炭学报, 2017, 42(3): 613−620.
XIE K N, JIANG D Y, JIANG X, et al. Analysis of energy distribution and critical characteristics of shale splitting test in Brazil[J]. Journal of Coal Industry, 2017, 42(3): 613−620.
[26] 杜坤, 李地元, 金解放. 充填体与岩体能量和强度匹配的分析及应用[J]. 中国安全科学学报, 2011, 21(12): 82−87. doi: 10.3969/j.issn.1003-3033.2011.12.012
DU K, LI D Y, JIN J F. Matching analysis of energy and strength between backfill and rock mass and its application[J]. China Safety Science Journal, 2011, 21(12): 82−87. doi: 10.3969/j.issn.1003-3033.2011.12.012
[27] 刘志祥, 李夕兵, 赵国彦, 等. 充填体与岩体三维能量耗损规律及合理匹配[J]. 岩石力学与工程学报, 2010, 29(2): 344−348.
LIU Z X, LI X B, ZHAO G Y, et al. Three−dimensional energy dissipation laws and reasonable matches between backfill and rock mass[J]. Chinese Journal of Rock Mechanics and Engineering, 2010. 29(2): 344−348.
[28] DENG J, LI B, LI X B. et al. Analysis of factors and countermeasures of mining subsidence in Kaiyang Phosphorus Mine[J]. J Cent. South Univ. Technol., 2006, 13: 733–737.
[29] SONG X P, LI J B, WANG S, et al. Study of mechanical behavior and cracking mechanism of prefabricated fracture cemented paste backfill under different loading rates from the perspective of energy evolution[J]. Constr. Build. Mater., 2022, 361: 129737.
[30] QI W Y, ZHANG J X, ZHOU N, et al. Mechanism by which backfill body reduces amount of energy released in deep coal mining[J]. Shock and Vibration, 2019, 14: 8253269.
[31] LIU L, XIN J, QI C C, KI−IL SONG, et al. Experimental investigation of mechanical, hydration, microstructure and electrical properties of cemented paste backfill[J]. Constr. Build. Mater., 2020, 263: 120137.
[32] 谢和平, 鞠杨, 黎立云. 基于能量耗散与释放原理的岩石强度与整体破坏准则[J]. 岩石力学与工程学报, 2005, 24(17): 3003−3010.
XIE H P, JU Y, LI L Y. Criteria for strength and structural failure of rocks based on energy dissipation and energy release principles[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(17): 3003−3010.
[33] XIAO S, WANG H L, LIU B, et al. The surface−forming energy release rate based fracture criterion for elastic–plastic crack propagation[J]. J. Mech. Phys. Solids., 2015, 84: 336−357.
[34] 彭瑞东, 谢和平, 鞠杨. 砂岩拉伸过程中的能量耗散与损伤演化分析[J]. 岩石力学与工程学报, 2007, 26(12): 2526−2531. doi: 10.3321/j.issn:1000-6915.2007.12.019
PENG R D, XIE H P, JU Y. Analysis of energy. dissipation and damage evolution of sandstone during tensile process[J]. Chinese Journal of Rock Mechanics and Engineering, 2007, 26(12): 2526−2531. doi: 10.3321/j.issn:1000-6915.2007.12.019
[35] T NISHIOKA, S SYANO, T FUJIMOTO. Concepts of separated j-integrals, separated energy release rates, and the component separation method of the J-integral for interfacial fracture mechanics[J]. J. Appl. Mech., 2003, 70(4): 505–516.
[36] 卢开放,侯正猛,孙伟,等. 云南省矿井抽水蓄能电站潜力评估与建设关键技术[J]. 工程科学与技术, 2022,54(1):136-144.
LU K F, HOU Z M, SUN W, et al. Key technologies for potential evaluation and construction of mine pumped storage power stations in Yunnan Province[J]. Engineering Science and Technology, 2022, 54 (1): 136-144.
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