Experimental study on unloading confining pressure deformation and damage failure of multi-source coal-based solid waste cemented backfill

Authors

HE Xiang, School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China; State Key Laboratory for Safe Mining of Deep Coal Resources and Environmental Protection, Anhui University of Science and Technology, Huainan 232001, ChinaFollow
WEI Longqiang, School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China; State Key Laboratory for Safe Mining of Deep Coal Resources and Environmental Protection, Anhui University of Science and Technology, Huainan 232001, China
YANG Ke, School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China; State Key Laboratory for Safe Mining of Deep Coal Resources and Environmental Protection, Anhui University of Science and Technology, Huainan 232001, ChinaFollow
ZHANG Tong, School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China; State Key Laboratory for Safe Mining of Deep Coal Resources and Environmental Protection, Anhui University of Science and Technology, Huainan 232001, China
ZHANG Cun, School of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
ZHANG Zilong, School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China; State Key Laboratory for Safe Mining of Deep Coal Resources and Environmental Protection, Anhui University of Science and Technology, Huainan 232001, China
CHEN Yanjun, School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China; State Key Laboratory for Safe Mining of Deep Coal Resources and Environmental Protection, Anhui University of Science and Technology, Huainan 232001, China

Abstract

Objective The preparation of multi-source coal-based solid waste into filling materials for interval strip filling mining is one of the important means of green coal mining. The deformation and failure law of multi-source coal-based solid waste cemented backfill during strip coal pillar mining directly affects the stability of the stope.Methods Five typical solid wastes were mixed with cement to prepare cemented backfill. The conventional triaxial and constant axial pressure unloading confining pressure stress tests of backfill specimens were carried out. The stress-strain curves and failure characteristics of backfill under two stress loading paths were analyzed. The evolution law of deformation parameters with confining pressure during unloading confining pressure was explored, and the unloading damage mechanism and strength criterion of backfill were revealed. Results and Conclusions The results show that: (1) The backfill specimens show brittle failure characteristics in the conventional triaxial test. The cracks gradually develop and rapidly expand during failure. The brittle failure characteristics in the unloading confining pressure test are enhanced. The strain change value before the failure of the specimen is less than 6.5% of the failure. (2) In the process of unloading confining pressure, the volume deformation of the filling body specimen changes from compression to expansion, the deformation modulus decreases by 10% of the failure stage, and the Poisson’s ratio breaks through the elastic-plastic material limit of 0.5 when the specimen is destroyed. (3) The confining pressure difference ratio decreases linearly with the initial confining pressure, which indicates that the backfill is more likely to be destroyed under high confining pressure environment, and the evolution of damage factor D is highly synchronized with Poisson’s ratio. (4) The Mogi-Coulomb strength criterion is suitable for the triaxial test of backfill specimens under constant axial compression and unloading confining pressure. The unloading behavior has a weakening effect on the cohesion of the backfill, and has a strengthening effect on the internal friction angle. The research results provide a reference for the stability control of interval strip filling mining.

Keywords

triaxial unloading confining pressure, multi-source coal-based solid waste, cemented backfill, damage evolution, Mogi-Coulomb strength criterion

DOI

10.12363/issn.1001-1986.25.01.0049

Recommended Citation

HE Xiang, WEI Longqiang, YANG Ke, et al. (2025) "Experimental study on unloading confining pressure deformation and damage failure of multi-source coal-based solid waste cemented backfill," Coal Geology & Exploration: Vol. 53: Iss. 5, Article 15.
DOI: 10.12363/issn.1001-1986.25.01.0049
Available at: https://cge.researchcommons.org/journal/vol53/iss5/15

Reference

[1] 陈洋. 深井条带充填开采冲击地压发生机制与防治研究[J]. 岩石力学与工程学报，2024，43(8)：2079.

CHEN Yang. Rockburst occurrence and control in deep longwall coal panels with backfill skipping mining[J]. Chinese Journal of Rock Mechanics and Engineering，2024，43(8)：2079.

[2] 白二虎，郭文兵，谭毅，等. “条采留巷充填法”绿色协调开采技术[J]. 煤炭学报，2018，43(增刊1)：21−27.

BAI Erhu，GUO Wenbing，TAN Yi，et al. Green coordinated mining technology of strip mining roadway backfilling method[J]. Journal of China Coal Society，2018，43(Sup.1)：21−27.

[3] 杨科，赵新元，何祥，等. 多源煤基固废绿色充填基础理论与技术体系[J]. 煤炭学报，2022，47(12)：4201−4216.

YANG Ke，ZHAO Xinyuan，HE Xiang，et al. Basic theory and key technology of multi–source coal–based solid waste for green backfilling[J]. Journal of China Coal Society，2022，47(12)：4201−4216.

[4] ZHAO Xinyuan，YANG Ke，HE Xiang，et al. Mix proportion and microscopic characterization of coal–based solid waste backfill material based on response surface methodology and multi–objective decision–making[J]. Scientific Reports，2024，14(1)：5672.

[5] 唐岳松，张令非，吕华永. 煤基固废制备充填材料配比优化试验研究[J]. 矿业科学学报，2019，4(4)：327−336.

TANG Yuesong，ZHANG Lingfei，LYU Huayong. Study on proportion optimization of coal–based solid wastes filling materials[J]. Journal of Mining Science and Technology，2019，4(4)：327−336.

[6] ZHANG Jiqiang，YANG Ke，HE Xiang，et al. Study on mechanical properties and damage characteristics of coal–based solid waste cemented backfill[J]. Construction and Building Materials，2023，368：130373.

[7] 冯国瑞，解文硕，郭育霞，等. 早期受载对矸石胶结充填体力学特性及损伤破坏的影响[J]. 岩石力学与工程学报，2022，41(4)：775−784.

FENG Guorui，XIE Wenshuo，GUO Yuxia，et al. Effect of early load on mechanical properties and damage of cemented gangue backfill[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(4)：775−784.

[8] 李晓磊，杜献杰，冯国瑞，等. 水泥–粉煤灰基矸石胶结充填体破坏特征及强度形成机制[J]. 煤炭科学技术，2024，52(5)：36−45.

LI Xiaolei，DU Xianjie，FENG Guorui，et al. Failure characteristics and strength formation mechanism of cement–fly ash based cemented gangue backfill[J]. Coal Science and Technology，2024，52(5)：36−45.

[9] 冯国瑞，赵永辉，郭育霞，等. 柱式充填体单轴压缩损伤演化及破坏特征研究[J]. 中南大学学报(自然科学版)，2022，53(10)：4012−4023.

FENG Guorui，ZHAO Yonghui，GUO Yuxia，et al. Study on damage evolution and failure characteristics of backfill column under uniaxial compression[J]. Journal of Central South University (Science and Technology)，2022，53(10)：4012−4023.

[10] 华心祝，常贯峰，刘啸，等. 多源煤基固废充填体强度演化规律及声发射特征[J]. 岩石力学与工程学报，2022，41(8)：1536−1551.

HUA Xinzhu，CHANG Guanfeng，LIU Xiao，et al. Strength evolution law and acoustic–emission characteristics of multi–source coal–based filling body of solid wastes[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(8)：1536−1551.

[11] 文志强，杨科，何祥，等. 多源煤基固废充填体固结与承载性能的温度效应研究[J]. 煤矿安全，2024，55(4)：134−142.

WEN Zhiqiang，YANG Ke，HE Xiang，et al. Research on temperature effect of consolidation and bearing capacity of multi–source coal–based solid waste backfill[J]. Safety in Coal Mines，2024，55(4)：134−142.

[12] 杨科，张继强，何祥，等. 多源煤基固废胶结充填体力学及变形破坏特征试验研究[J]. 煤田地质与勘探，2024，52(6)：102−114.

YANG Ke，ZHANG Jiqiang，HE Xiang，et al. Experimental study on the mechanics and deformation failure characteristics of multi–source coal–based solid waste cemented backfill[J]. Coal Geology & Exploration，2024，52(6)：102−114.

[13] 程爱平，付子祥，邓代强，等. 高低应力水平下胶结充填体蠕变特征及分数阶本构模型[J]. 中国矿业大学学报，2023，52(2)：276−285.

CHENG Aiping，FU Zixiang，DENG Daiqiang，et al. Creep characteristics and fractional order constitutive model of cemented backfill under high and low stress levels[J]. Journal of China University of Mining & Technology，2023，52(2)：276−285.

[14] WU Di，ZHAO Runkang，HOU Wentao，et al. A coupled thermo–mechanical damage modeling application of cemented coal gangue–fly ash backfill under uniaxial compression[J]. Arabian Journal for Science and Engineering，2020，45(5)：3469−3478.

[15] WU Di，ZHAO Runkang，QU Chunlai. Effect of curing temperature on mechanical performance and acoustic emission properties of cemented coal gangue–fly ash backfill[J]. Geotechnical and Geological Engineering，2019，37(4)：3241−3253.

[16] LIU Weizhen，CHEN Juntao，GUO Zhongping，et al. Mechanical properties and damage evolution of cemented coal gangue–fly ash backfill under uniaxial compression：Effects of different curing temperatures[J]. Construction and Building Materials，2021，305：124820.

[17] 李建林，王乐华. 节理岩体卸荷非线性力学特性研究[J]. 岩石力学与工程学报，2007，26(10)：1968−1975.

LI Jianlin，WANG Lehua. Study on unloading nonlinear mechanical characteristics of jointed rock mass[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(10)：1968−1975.

[18] 张宏博，宋修广，黄茂松，等. 不同卸荷应力路径下岩体破坏特征试验研究[J]. 山东大学学报(工学版)，2007，37(6)：83−86.

ZHANG Hongbo，SONG Xiuguang，HUANG Maosong，et al. Research on failure features of rocks under different stress unloading path[J]. Journal of Shandong University (Engineering Science)，2007，37(6)：83−86.

[19] MENG Yaoyao，JING Hongwen，LIU Xiaowei，et al. Effects of initial unloading level on the mechanical，micro failure and energy evolution characteristics of stratified rock mass under triaxial unloading confining pressure[J]. Theoretical and Applied Fracture Mechanics，2023，128：104161.

[20] 丛宇，王在泉，郑颖人，等. 卸围压路径下大理岩破坏过程的声发射特性试验研究[J]. 西南交通大学学报，2014，49(1)：97−104.

CONG Yu，WANG Zaiquan，ZHENG Yingren，et al. Experimental study on acoustic emission features of marbles during unloading failure process[J]. Journal of Southwest Jiaotong University，2014，49(1)：97−104.

[21] 刘泉声，刘恺德，卢兴利，等. 高应力下原煤三轴卸荷力学特性研究[J]. 岩石力学与工程学报，2014，33(增刊2)：3429−3438.

LIU Quansheng，LIU Kaide，LU Xingli，et al. Study of mechanical properties of raw coal under high stress with triaxial unloading[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(Sup.2)：3429−3438.

[22] 刘泉声，刘恺德，朱杰兵，等. 高应力下原煤三轴压缩力学特性研究[J]. 岩石力学与工程学报，2014，33(1)：24−34.

LIU Quansheng，LIU Kaide，ZHU Jiebing，et al. Study of mechanical properties of raw coal under high stress with triaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(1)：24−34.

[23] 许江，李波波，周婷，等. 加卸载条件下煤岩变形特性与渗透特征的试验研究[J]. 煤炭学报，2012，37(9)：1493−1498.

XU Jiang，LI Bobo，ZHOU Ting，et al. Experimental study of coal deformation and permeability characteristics under loading–unloading conditions[J]. Journal of China Coal Society，2012，37(9)：1493−1498.

[24] LIU Weizhen，HU Zhongjing，LIU Chao，et al. Mechanical properties under triaxial compression of coal gangue–fly ash cemented backfill after cured at different temperatures[J]. Construction and Building Materials，2024，411：134268.

[25] LIU Weizhen，WANG Qingbiao，GE Haibin，et al. Mechanical properties of cemented backfill under different unloading rates after cured at different temperatures[J]. Construction and Building Materials，2024，413：134849.

[26] 田文岭，杨圣奇，方刚. 煤样三轴循环加卸载力学特征颗粒流模拟[J]. 煤炭学报，2016，41(3)：603−610.

TIAN Wenling，YANG Shengqi，FANG Gang. Particle flow simulation on mechanical behavior of coal specimen under triaxial cyclic loading and unloading[J]. Journal of China Coal Society，2016，41(3)：603−610.

[27] 宋卫东，汪杰，谭玉叶，等. 三轴加–卸载下分层充填体能耗及损伤特性[J]. 中国矿业大学学报，2017，46(5)：1050−1057.

SONG Weidong，WANG Jie，TAN Yuye，et al. Energy consumption and damage characteristics of stratified backfill under triaxial loading and unloading[J]. Journal of China University of Mining & Technology，2017，46(5)：1050−1057.

[28] 邹尤森，杨天雨，张希. 循环加卸载下尾砂胶结充填体力学参数变化特征的试验研究与分析[J]. 价值工程，2020，39(11)：276−280.

ZOU Yousen，YANG Tianyu，ZHANG Xi. Experimental study and analysis on variation characteristics of mechanical parameters of tailings filled material under cyclic loading and unloading[J]. Value Engineering，2020，39(11)：276−280.

[29] WANG Jie，FU Jianxin，SONG Weidong. Mechanical properties and microstructure of layered cemented paste backfill under triaxial cyclic loading and unloading[J]. Construction and Building Materials，2020，257：119540.

[30] 杨科，魏祯，赵新元，等. 黄河流域煤电基地固废井下绿色充填开采理论与技术[J]. 煤炭学报，2021，46(增刊2)：925−935.

YANG Ke，WEI Zhen，ZHAO Xinyuan，et al. Theory and technology of green filling of solid waste in underground mine at coal power base of Yellow River Basin[J]. Journal of China Coal Society，2021，46(Sup.2)：925−935.

[31] 赵新元，杨科，何祥，等. 基于RSM–BBD的多源煤基固废胶结体配比及性能研究[J]. 材料导报，2024，38(9)：22090099.

ZHAO Xinyuan，YANG Ke，HE Xiang，et al. Study on proportioning and performance of cemented body from multi–source coal–based solid waste based on RSM–BBD experiment[J]. Materials Reports，2024，38(9)：22090099.

[32] 王云飞，黄正均，崔芳. 煤岩破坏过程的细观力学损伤演化机制[J]. 煤炭学报，2014，39(12)：2390−2396.

WANG Yunfei，HUANG Zhengjun，CUI Fang. Damage evolution mechanism in the failure process of coal rock based on mesomechanics[J]. Journal of China Coal Society，2014，39(12)：2390−2396.

[33] 董红娟，王博，张金山，等. 粉煤灰基复合胶凝喷浆材料的强度及水化机理[J]. 硅酸盐通报，2020，39(10)：3293−3297.

DONG Hongjuan，WANG Bo，ZHANG Jinshan，et al. Strength and hydration mechanism of fly ash–based composite cementitious shotcrete material[J]. Bulletin of the Chinese Ceramic Society，2020，39(10)：3293−3297.

[34] 朱子涵，蔚立元，李景龙，等. 峰前卸荷大理岩变形演化规律及破坏耗能特征[J]. 煤炭学报，2020，45(增刊1)：181−190.

ZHU Zihan，YU Liyuan，LI Jinglong，et al. Deformation evolution and dissipated energy characteristics of marble under pre–peak unloading conditions[J]. Journal of China Coal Society，2020，45(Sup.1)：181−190.

[35] 刘炜震，郭忠平，黄万朋，等. 不同温度养护后胶结充填体三轴卸围压力学特性试验研究[J]. 岩石力学与工程学报，2022，41(11)：2268−2282.

LIU Weizhen，GUO Zhongping，HUANG Wanpeng，et al. Experimental study on mechanical characteristics of cemented backfill under triaxial unloading confining pressure after cured at different temperatures[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(11)：2268−2282.

[36] 黄润秋，黄达. 卸荷条件下花岗岩力学特性试验研究[J]. 岩石力学与工程学报，2008，27(11)：2205−2213.

HUANG Runqiu，HUANG Da. Experimental research on mechanical properties of granites under unloading condition[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(11)：2205−2213.

[37] 冯友良. 大断面煤巷开挖卸荷帮部破坏机制与控制技术研究[D]. 北京：中国矿业大学(北京)，2017.

FENG Youliang. Study on rib breakage mechanism and control technology of large cross–section coal roadway for excavation unloading[D]. Beijing：China University of Mining & Technology (Beijing)，2017.

[38] 冯友良，鞠文君. 加卸荷应力路径下巷帮煤体力学特性与损伤破坏研究[J]. 煤炭科学技术，2019，47(4)：210−217.

FENG Youliang，JU Wenjun. Study on mechanical characteristics and damage failure of coal mass from roadway side wall under loading and unloading stress path[J]. Coal Science and Technology，2019，47(4)：210−217.

[39] 贾彦杰，蒋平，童华. 基于Drucker–Prager准则的扩孔器单齿正交切削岩土三维力学模型[J]. 岩土力学，2013，34(5)：1429−1436.

JIA Yanjie，JIANG Ping，TONG Hua. 3D mechanical modeling of soil orthogonal cutting under a single reamer cutter based on Drucker–Prager criterion[J]. Rock and Soil Mechanics，2013，34(5)：1429−1436.

[40] AL–AJMI A M，ZIMMERMAN R W. Relation between the Mogi and the coulomb failure criteria[J]. International Journal of Rock Mechanics and Mining Sciences，2005，42(3)：431−439.

[41] 杨科，方珏静，张吉雄，等. 加浆改性固体充填材料承载压缩特性与固结机制[J]. 中国矿业大学学报，2024，53(3)：456−468

YANG Ke，FANG Juejing，ZHANG Jixiong，et al. Compression load–bearing characteristics and consolidation mechanism of grout–modified solid backfill materials[J]. Journal of China University of Mining & Technology，2024，53(3)：456−468.

[42] 王云飞，焦华喆，李震，等. 白砂岩卸围压强度与损伤破坏特征[J]. 煤炭学报，2020，45(8)：2787−2794.

WANG Yunfei，JIAO Huazhe，LI Zhen，et al. Strength and damage failure characteristics of white sandstone under unloading confining pressure[J]. Journal of China Coal Society，2020，45(8)：2787−2794.

[43] 路彬. 连采连充式胶结充填采煤覆岩移动规律及控制对策研究[D]. 北京：中国矿业大学(北京)，2022.

LU Bin. Movement law and control strategy of overlying strata with cemented backfilling mining technology using continuous mining and continuous backfilling method[D]. Beijing：China University of Mining & Technology (Beijing)，2022.

[44] 朱晓峻. 带状充填开采岩层移动机理研究[D]. 徐州：中国矿业大学，2016.

ZHU Xiaojun. Study on strata movement mechanism in backfill–strip mining[D]. Xuzhou：China University of Mining & Technology，2016.