Study on mechanical properties of coal before and after flooding considering bedding direction
-
摘要:
层理弱面及煤岩遇水软化会导致煤岩力学性质降低,对煤矿地下水库稳定性、煤矿突透水事故防治等具有重要影响。为了研究层理及浸水对煤岩力学性质的综合影响,通过无损浸水试验与单轴压缩试验,并基于数字图像相关(Digital Image Correlation,DIC)技术,分析不同浸水条件下煤岩单轴压缩变形及破坏特性,获得了轴向平行和轴向垂直两种层理煤岩在天然状态、自然吸水以及强制吸水三种状态下的力学性质参数和表面应变场信息等。研究结果表明:煤岩的吸水特性呈现出明显的层理性差异,力学性质受到层理和浸水共同影响作用,具体如下:①毛细管作用导致轴向平行层理煤岩吸水能力强于轴向垂直层理煤岩,轴向平行层理煤岩的自然极限吸水率是轴向垂直层理煤岩的2.2倍;②煤岩的单轴抗压强度和弹性模量受层理影响为主,受浸水影响为辅,破坏模式与层理方向有关系,轴向垂直煤岩为剪切破坏,轴向平行煤岩为劈裂破坏,相同层理煤岩浸水前后破坏模式不变;③煤岩破坏是由均匀变形向非均匀变形转化的过程,浸水后煤岩会更早出现应变集中区,其压密阶段延长、弹性变形阶段缩短。研究结果有助于进一步理解轴向平行和轴向垂直两种层理煤岩浸水特性、力学性质及破裂演化规律,对地下水库预留煤柱保护、稳定性分析等相关工程实践具有一定的借鉴作用。
Abstract:The weak bedding plane and the water-softening coal will lead to the decrease in mechanical properties, which has an important influence on the stability of underground reservoirs and the prevention and control of water inrush accidents in coal mine. To study the comprehensive influence of bedding and soaking on the mechanical properties of coal, the uniaxial compression deformation and failure characteristics of coal under different soaking conditions were analyzed through a non-destructive soaking test and uniaxial compression test and based on the Digital image correlation method (DIC). The mechanical property parameters and surface strain field information of axial parallel and vertical bedded coal samples in the natural state, natural water absorption and forced water absorption were obtained. The results shown that the water absorption characteristics of coal shown obvious stratification differences, and the mechanical properties were affected by the combined effects of stratification and soaking. The specific results were as follows, ① Capillary action led to stronger water adsorption in axial parallel-bedded coal than in axial vertical-bedded coal, and the natural limiting water absorption rate of axial parallel-bedded coal was 2.2 times higher than that of axial vertical-bedded coal. ② The uniaxial compressive strength and elastic modulus of coal were mainly affected by bedding and supplemented by soaking. The failure mode was related to the direction of bedding. The failure mode of axial vertical coal was shear failure, while that of axial parallel coal was split failure. ③ The coal failure was a process of transformation from uniform to non-uniform deformation. After water soaking, the coal appeared strain concentration area earlier, its compaction stage was prolonged, and the elastic deformation stage was shortened. The research results were helpful to further understand the water soaking characteristics, mechanical properties, and rupture evolution of axial parallel and vertical bedded coals, and can be used as a reference for the protection and stability analysis of reserved coal pillars in underground reservoirs.
-
-
表 1 试验煤岩基础物理性质
Table 1 Physical properties of coal samples
方向 状态 煤岩编号 质量/g 高度/mm 直径/mm 体积/cm3 密度/(g·cm−3) 纵波波速/(km·s−1) 平行层理 未浸水 P0-1 258.9 100.51 49.64 194.42 1.33 2.032 P0-2 248.4 100.31 49.71 194.58 1.28 1.969 P0-3 260.5 100.46 49.68 194.64 1.34 2.033 浸水 P1-1 254.0 99.77 49.76 193.92 1.31 2.049 P1-2 249.0 100.31 49.70 194.50 1.28 2.033 P1-3 256.4 100.24 49.69 194.29 1.32 2.119 垂直层理 未浸水 T0-1 256.1 100.05 49.60 193.22 1.33 1.969 T0-2 257.0 99.43 49.56 191.71 1.34 1.969 T0-3 252.8 100.16 49.61 193.51 1.31 1.966 浸水 T1-1 267.4 100.14 49.61 193.47 1.38 2.066 T1-2 253.2 99.68 49.61 192.58 1.31 1.969 T1-3 255.2 100.04 49.61 193.28 1.32 1.953 表 2 煤岩单轴压缩力学性质
Table 2 Mechanical properties of coal and rock under uniaxial compression
方向 状态 煤岩编号 峰值强
度/MPa强度均
值/MPa弹性模
量/MPa模量均
值/MPa平行
层理未
浸
水P0-1 18.17 19.96 2327.89 2243.56 P0-2 26.62 19.96 2358.19 P0-3 15.09 19.96 2044.59 浸
水P1-1 15.56 20.10 2215.08 2270.34 P1-2 21.90 20.10 2232.66 P1-3 22.83 20.10 2363.27 垂直
层理未
浸
水T0-1 30.84 33.18 2851.81 2858.49 T0-2 38.93 33.18 2999.12 T0-3 29.78 33.18 2724.54 浸
水T1-1 39.65 30.62 2910.08 2769.10 T1-2 24.92 30.62 2689.22 T1-3 27.29 30.62 2708.01 表 3 煤岩各阶段应力占比
Table 3 Table of stress proportion in each stage of coal samples
方向 状态 煤岩编号 压密阶段 弹性阶段 非稳定阶段 压密应
力/MPa压密阶
段占比/%占比均
值/%应力
水平/%起裂应
力/MPa弹性阶
段占比/%占比均
值/%应力
水平/%表观破裂
应力/MPa非稳定阶
段占比/%占比均
值/%应力
水平/%平行层理 未浸水 P0-1 4.49 24.71 29.93 29.93 7.47 16.40 17.00 46.93 15.77 58.89 53.07 91.06 P0-2 9.88 37.11 15.4 20.74 23.65 42.15 P0-3 4.22 27.97 6.31 13.85 14.72 58.18 浸水 P1-1 5.57 35.80 32.66 32.66 7.60 13.05 13.44 46.10 15.56 51.16 53.90 98.27 P1-2 7.72 35.25 10.64 13.33 21.58 51.42 P1-3 6.15 26.94 9.33 13.93 21.98 59.13 垂直层理 未浸水 T0-1 9.86 31.97 26.35 26.35 14.67 15.60 15.75 42.11 23.05 52.43 57.89 74.19 T0-2 10.03 25.76 16.07 15.52 25.46 58.72 T0-3 6.35 21.32 11.16 16.15 24.55 62.53 浸水 T1-1 17.40 43.88 39.59 39.59 22.11 11.88 14.37 53.95 34.35 44.24 46.05 87.35 T1-2 8.76 35.15 12.97 16.89 22.20 47.95 T1-3 10.84 39.72 14.75 14.33 23.56 45.95 -
[1] CHENG Yuanping,PAN Zhejun. Reservoir properties of chinese tectonic coal: a review[J]. Fuel,2020,260:116350.
[2] 赵 科. 煤体结构面剪切力学特性的数值模拟研究[J]. 煤炭科学技术,2021,49(12):89−95. ZHAO Ke. Numerical simulation of shear mechanical properties of coal structural plane[J]. Coal Science and Technology,2021,49(12):89−95.
[3] 郝宪杰,魏英楠,杨 科,等. 煤储集层起裂强度和损伤强度的各向异性特征[J]. 石油勘探与开发,2021,48(1):211−221. HAO Xianjie,WEI Yingnan,YANG Ke,et al. Anisotropy of crack initiation strength and damage strength of coal reservoirs[J]. Petroleum Exploration and Development,2021,48(1):211−221.
[4] 卢志国,鞠文君,王 浩,等. 硬煤冲击倾向各向异性特征及破坏模式试验研究[J]. 岩石力学与工程学报,2019,38(4):757−768. LU Zhiguo,JU Wenjun,WANG Hao,et al. Experimental study on anisotropic characteristics of impact tendency and failure model of hard coal[J]. Chinese Journal of Rock Mechanics and Engineering,2019,38(4):757−768.
[5] SUN Changlun,LI Guichen,ZHANG Suhui,et al. Mechanical and heterogeneous properties of coal and rock quantified and mapped at the microscale[J]. Applied Sciences,2020,10(1):342. doi: 10.3390/app10010342
[6] 顾大钊,张 勇,曹志国. 我国煤炭开采水资源保护利用技术研究进展[J]. 煤炭科学技术,2016,44(1):1−7. GU Dazhao,ZHANG Yong,CAO Zhiguo. Technical progress of water resource protection and utilization by coal mining in China[J]. Coal Science and Technology,2016,44(1):1−7.
[7] 顾大钊,李 庭,李井峰,等. 我国煤矿矿井水处理技术现状与展望[J]. 煤炭科学技术,2021,49(1):11−18. GU Dazhao,LI Ting,LI Jingfeng,et al. Current status and prospects of coal mine water treatment technology in China[J]. Coal Science and Technology,2021,49(1):11−18.
[8] 姜琳婧,方 杰,杨 宗,等. 基于GIS与CAD的煤矿地下水库库容计算平台开发研究[J]. 煤炭科学技术,2020,48(11):166−171. doi: 10.13199/j.cnki.cst.2020.11.021 JIANG Linjing,FANG Jie,YANG Zong,et al. Study on precision computing platform development of coal mine underground reservoir capacity based on GIS and CAD[J]. Coal Science and Technology,2020,48(11):166−171. doi: 10.13199/j.cnki.cst.2020.11.021
[9] 李 磊,李宏艳,李凤明,等. 层理角度对硬煤冲击倾向性影响的实验研究[J]. 采矿与安全工程学报,2019,36(5):987−994. LI Lei,LI Hongyan,LI Fengming,et al. Experimental study of the effect of bedding angle on hard coal bursting liability[J]. Journal of Mining and Safety Engineering,2019,36(5):987−994.
[10] 刘忠玉,董 旭,张旭阳. 分级循环荷载下层理煤岩力学特性试验研究[J]. 岩石力学与工程学报,2021,40(S1):2593−2602. LIU Zhongyu,DONG Xu,ZHANG Xuyang. Experimental study on mechanical properties of bedding coal and rock under graded cyclic loading[J]. Chinese Journal of Rock Mechanics and Engineering,2021,40(S1):2593−2602.
[11] 刘恺德,刘泉声,朱元广,等. 考虑层理方向效应煤岩巴西劈裂及单轴压缩试验研究[J]. 岩石力学与工程学报,2013,32(2):308−316. doi: 10.3969/j.issn.1000-6915.2013.02.012 LIU Kaide,LIU Quansheng,ZHU Yuanguang,et al. Experimental study of coal considering directivity effect of bedding plane under brazilian splitting and uniaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering,2013,32(2):308−316. doi: 10.3969/j.issn.1000-6915.2013.02.012
[12] 王 伟,赵毅鑫,高艺瑞,等. 层理和预制裂纹方向对煤断裂力学性质影响规律试验研究[J]. 岩石力学与工程学,2022,41(3):433−445. WANG Wei,ZHAO Yixin,GAO Yirui,et al. Experimental research of influences of bedding and pre-crack directions on fracture characteristics of coal[J]. Rock Mechanics and Engineering,2022,41(3):433−445.
[13] 龚 爽,赵毅鑫,王 震,等. 层理对煤岩动态裂纹扩展分形特征的影响[J]. 煤炭学报,2021,46(8):2574−2582. GONG Shuang,ZHAO Yixin,WANG Zhen,et al. Effect of bedding on the fractal characteristics of dynamic crack propagation in coal rocks[J]. Journal of China Coal Society,2021,46(8):2574−2582.
[14] 陈 田,姚强岭,杜 茂,等. 浸水次数对煤样裂隙发育损伤的实验研究[J]. 岩石力学与工程学报,2016,35(S2):3756−3762. CHEN Tian,YAO Qiangling,DU Mao,et al. Experimental research of effect of water intrusion times on crack propagation in coal[J]. Chinese Journal of Rock Mechanics and Engineering,2016,35(S2):3756−3762.
[15] 汤传金. 干湿循环及酸性水环境影响下煤样损伤特征研究[D]. 徐州: 中国矿业大学, 2020. TANG Chuanjin. Study on damage characteristics of coal under the influence of dryness-saturation cycles and acid water environment[D]. Xuzhou: China University of Mining and Technology, 2020.
[16] 来兴平,张 帅,代晶晶,等. 水力耦合作用下煤岩多尺度损伤演化特征[J]. 岩石力学与工程学报,2020,39(S2):3217−3228. LAI Xingping,ZHANG Shuai,DAI Jingjing,et al. Multi-scale damage evolution characteristics of coal and rock under hydraulic coupling[J]. Chinese Journal of Rock Mechanics and Engineering,2020,39(S2):3217−3228.
[17] 姚强岭,王伟男,李学华,等. 水-岩作用下含煤岩系力学特性和声发射特征研究[J]. 中国矿业大学学报,2021,50(3):558−569. YAO Qiangling,WANG Weinan,LI Xuehua,et al. Study of mechanical properties and acoustic emission characteristics of coal measures under water-rock interaction[J]. Journal of China University of Mining and Technology,2021,50(3):558−569.
[18] 李波波,王忠晖,任崇鸿,等. 水−力耦合下煤岩力学特性及损伤本构模型研究[J]. 岩土力学,2021,42(2):315−323. LI Bobo,WANG Zhonghui,Ren Chonghong,et al. Mechanical properties and damage constitutive model of coal under the coupled hydro-mechanical effect[J]. Rock and Soil Mechanics,2021,42(2):315−323.
[19] 唐书恒,颜志丰,朱宝存,等. 饱和含水煤岩单轴压缩条件下的声发射特征[J]. 煤炭学报,2010,35(1):37−41. TANG Shuheng,YAN Zhifeng,ZHU Baocun,et al. Acoustic emission characteristics of water-saturated coals in uniaxial compression experiment[J]. Journal of China Coal Society,2010,35(1):37−41.
[20] 李建华. 煤矿地下水库储水浸泡对煤柱坝体强度影响的试验研究[J]. 煤矿开采,2018,23(3):15−17. LI Jianhua. Experimental study of water storage soaking of coal mine underground reservoir to coal pillar dam body strength[J]. Coal Mining Technology,2018,23(3):15−17.
[21] 姚强岭,郝 琪,陈翔宇,等. 煤矿地下水库煤柱坝体宽度设计[J]. 煤炭学报,2019,44(3):891−899. YAO Qiangling,HAO Qi,CHEN Xiangyu,et al. Design on the width of coal pillar dam in coal mine groundwater reservoir[J]. Journal of China Coal Society,2019,44(3):891−899.
[22] 赵 宇,张玉贵,于弘奕. 煤岩吸水率对声波速度各向异性影响的实验研究[J]. 石油地球物理勘探,2017,52(5):999−1004. doi: 10.13810/j.cnki.issn.1000-7210.2017.05.013 ZHAO Yu,ZHANG Yugui,YU Hongyi. Experimental study on the influence of water absorption rate of coal on the anisotropy of acoustic velocity[J]. Oil Geophysical Prospecting,2017,52(5):999−1004. doi: 10.13810/j.cnki.issn.1000-7210.2017.05.013
[23] 宋红华,赵毅鑫,姜耀东,等. 单轴受压条件下煤岩非均质性对其破坏特征的影响[J]. 煤炭学报,2017,42(12):3125−3132. doi: 10.13225/j.cnki.jccs.2017.0588 SONG Honghua,ZHAO Yixin,JIANG Yaodong,et al. Influence of heterogeneity on the failure characteristics of coal under uniaxial compression condition[J]. Journal of China Coal Society,2017,42(12):3125−3132. doi: 10.13225/j.cnki.jccs.2017.0588
[24] (美)森哲尔, (美)辛巴拉. 流体力学基础及其工程应用原书[M]. 第4版. 北京: 机械工业出版社, 2013. [25] ZHONG Chunlin,ZHANG Zhenyu,RANJITH P G,et al. The role of pore water plays in coal under uniaxial cyclic loading[J]. Engineering Geology,2019,257:105125. doi: 10.1016/j.enggeo.2019.05.002
[26] TANG Chuanjin,YAO Qiangling,LI Zhenyu,et al. Experimental study of shear failure and crack propagation in water-bearing coal samples[J]. Energy Science & Engineering,2019,7(5):2193−2204.
-
期刊类型引用(27)
1. 王志刚,马丁,杨震,贾帆帆. 改进型止浆塞在上斜钻孔带压封堵地质异常区中的应用研究. 煤炭技术. 2025(01): 167-170 . 百度学术
2. 王慧恩. 穿层瓦斯抽采钻孔渗流演化特征. 陕西煤炭. 2025(01): 37-40+63 . 百度学术
3. 朱卫兵,李竹,赵波智,郭春雷,宁杉. 矿山采空区卸压底板岩层资源化利用技术体系构建及展望. 煤炭学报. 2025(05): 2355-2366 . 百度学术
4. 孙赫. 穿层钻孔瓦斯抽采半径研究. 煤炭技术. 2024(03): 165-168 . 百度学术
5. 董相欢. 底板承压水上底抽巷破坏特征及控制技术. 陕西煤炭. 2024(06): 70-76 . 百度学术
6. 段东东. 底板承压水上底抽巷布置层位及围岩控制技术研究. 山东煤炭科技. 2024(07): 114-119 . 百度学术
7. 张建国,翟成,唐伟. 深井不同层位底板岩巷与煤巷相互影响研究. 煤炭工程. 2024(08): 1-6 . 百度学术
8. 刘军. 煤层群上下保护层开采围岩应力及裂隙演化规律研究. 矿业安全与环保. 2024(04): 56-63+73 . 百度学术
9. 高登云,李瑞群. 神东矿区综采工作面上隅角瓦斯治理技术研究. 煤炭工程. 2023(04): 87-91 . 百度学术
10. 郭建行. 近距离高瓦斯煤层群首采层“一面四巷”瓦斯治理技术. 煤炭工程. 2023(05): 70-75 . 百度学术
11. 胡亚超,熊祖强,王春,王成. 煤层顶板深孔预裂爆破高效封孔材料及工艺研究. 煤炭科学技术. 2023(04): 30-36 . 本站查看
12. 张超,范富槐,李树刚,翟成,江丙友,杨朴超,曾祥真. 基于微胶囊技术的瓦斯抽采钻孔密封材料研究. 煤炭科学技术. 2023(04): 72-79 . 本站查看
13. 武瑞龙. 复杂地层底板梳状定向钻孔抽采瓦斯技术研究. 煤炭工程. 2023(06): 79-82 . 百度学术
14. 温俊三. 赵庄矿底抽巷穿层钻孔偏斜规律研究. 山西煤炭. 2023(01): 13-18 . 百度学术
15. 刘军,张宪尚,张士岭. 煤层群上下保护层开采围岩应力时空演化规律及应用研究. 中国安全生产科学技术. 2023(06): 66-73 . 百度学术
16. 孙伟. 深部高应力底抽巷围岩破坏特征及控制技术研究. 山西冶金. 2023(06): 220-224 . 百度学术
17. 潘竞涛,刘长宇,赵丹,贾男,刘海金,任志保. 下行定向钻孔氮气泡沫幂律多相流携渣解堵技术. 煤炭科学技术. 2023(12): 298-309 . 本站查看
18. 赵学良,贾航,罗华贵. 赵庄煤矿工作面分源联合立体抽采技术应用研究. 煤炭工程. 2022(01): 74-79 . 百度学术
19. 包若羽. 松软煤层瓦斯抽采钻孔“同心环”加固密封技术研究与应用. 煤炭科学技术. 2022(05): 164-170 . 本站查看
20. 李高健,韦金龙,杨竹军,赵宝友. 密集抽采钻孔及浸水蠕变作用下底抽巷围岩控制技术研究. 煤炭工程. 2022(07): 44-49 . 百度学术
21. 马玉林,王常瑞,马凯. 红外加热储层煤岩热损伤特征扫描电镜及增透试验研究. 煤炭科学技术. 2022(07): 177-183 . 本站查看
22. 马雨坤. 瓦斯抽采钻孔精准防斜设备研究. 能源技术与管理. 2022(05): 142-144 . 百度学术
23. 马莉,石新莉,李树刚,林海飞,宋爽,代新冠. 基于MPC的瓦斯抽采智能调控模型研究. 煤炭科学技术. 2022(08): 82-90 . 本站查看
24. 张世阔,王力,李秀山,豆旭谦,田广生,张振雷,魏涛. 煤矿井下硬岩气动冲击回转钻进技术与装备. 煤炭技术. 2022(11): 5-8 . 百度学术
25. 李喜员,孙矩正,张益民,魏风清. 固液两相复合封孔技术在瓦斯抽采中的应用. 矿业安全与环保. 2022(05): 131-134 . 百度学术
26. 豆旭谦,姚宁平,李秀山,王力,张凯,魏宏超. 基于单柱齿破岩过程的高压液动冲击回转钻进试验研究. 煤田地质与勘探. 2022(12): 170-176 . 百度学术
27. 梁为民,李晓鹏,李敏敏. 冲击荷载作用下各向异性煤体中大孔结构变化规律研究. 煤炭科学技术. 2022(11): 100-109 . 本站查看
其他类型引用(5)