Study on Mechanical Constitutive Relationship and Damage Evolution of Gas-bearing Coal Based on Initial Pore-cracks
DING Xin1, XIAO Xiaochun1, WU Di1, Lyu Xiangfeng2, PAN Yishan1,3, BAI Runxin4
1 School of Mechanics and Engineering, Liaoning Technical University, Fuxin 123000, China 2 School of Civil and Resource Engineering, University of Science & Technology Beijing, Beijing 100083, China 3 School of Environment, Liaoning University, Shenyang 110136, China 4 School of Science & School of Pre-university, Dalian Minzu University, Dalian 116600, China
Abstract: Rockbursts and secondary gas disasters are more likely to occur in complex geological structures, under the combined action of varied in-situ stress, mining stress and gas, which is the instability process of the mechanical balance system of coal media. Thus, it is the foundation of coal dynamic disaster incubation and occurrence mechanism, that describing the mechanical relationship of gas-bearing coal loading process accurately. In this paper, the primary crack is considered, defined as the initial damage and its theoretical derivation formula characterized by porosity is obtained, for the deterioration on the mechanical properties of coal. The damage evolution equation and mechanical constitutive model of gas-bearing coal based on non-uniform statistical theory is constructed, which the parameter of initial porosity, expansion of coal matrix gas adsorbed, softening characteristics of gas seepage and true triaxial stress state is considered, and the influence on mechanical properties is analyzed qualitatively. The result show that, the higher initial porosity of coal, the grater of length, width and number of cracks in any section, it's easier to form stress concentration with the effective area reduced, thus, the damage curve had a higher value at peak and a slight decrease in the growth rate of the post peak. Otherwise, the higher the degree of homogeneity, the lower the damage value at the peak, the more lagging the damage evolution is, and the greater the slope of the damage evolution curve. The expansion stress generated by coal adsorption improved signifi-cantly, with the increase of gas pressure, and the adsorption parameters a, b also promote it. The elastic modulus and homogeneity have a positive correlation on the strength of coal, and the modulus of stress reduction at post-peak, which increases the risk of coal burst liability. Both initial damage and gas promote the development of cracks in coal and reduced the uniformity of its properties, and then, the strength and stress drop modulus at post-peak decrease, while the plastic characteristics become more prominent and promote softening, it's also the reason why the rockburst happened in high gas coal seam with the risk indicators lower than conventionality.
1 Pan Y S. Rockbust in coal mine, Science Press, China,2018(in Chinese). 潘一山. 煤矿冲击地压, 科学出版社, 2018. 2 Qi Q X, Li Y Z, Zhao S K, et al. Coal Science and Technology, 2019, 47(9), 1(in Chinese). 齐庆新, 李一哲, 赵善坤, 等. 煤炭科学技术, 2019, 47(9), 1. 3 Jiang Y D, Zhao Y X. Chinese Journal of Rock Mechanics and Enginee-ring, 2015, 34(11), 2188(in Chinese). 姜耀东,赵毅鑫. 岩石力学与工程学报, 2015, 34(11), 2188. 4 Wang S B, Zhang X. Journal of China Coal Society, 2008, 33(7), 738(in Chinese). 王胜本,张晓. 煤炭学报, 2008, 33(7), 738. 5 Liu X R, Xian X F. Coal Science and Technology, 2004, 32(8), 69(in Chinese). 刘新荣, 鲜学福.煤炭科学技术, 2004, 32(8), 69. 6 Pan Y S. Journal of China Coal Society, 2016, 41(1), 105(in Chinese). 潘一山.煤炭学报, 2016, 41(1), 105. 7 Wang Z, Yin G Z, Hu Q T, et al. Journal of Mining & Safety Enginee-ring, 2010, 27(4), 272(in Chinese). 王振, 尹光志, 胡千庭, 等.采矿与安全工程学报, 2010, 27(4), 272. 8 Zhang M T, Xu Z H, Pan Y S, et al. Journal of China Coal Society, 1991, 16(4), 48(in Chinese). 章梦涛, 徐曾和, 潘一山, 等. 煤炭学报, 1991, 16(4), 48. 9 Liang B, Zhang M T, Wang Y J. Roil and Soil Mechanics, 1995, 16(3), 22(in Chinese). 梁冰, 章梦涛, 王泳嘉.岩土力学, 1995, 16(3), 22. 10 Yun S, Palazotto A.Engineering Fracture Mechanics, 2007, 74, 2844. 11 Shao J F, Jia Y, Kondo D, et al. Mechanics of Materials, 2006, 38, 218. 12 Rashid K A A, Sun-Myung K. Engineering Fracture Mechanics, 2010, 77, 1577. 13 Zhu J, Jiang Y D, Zhao Y X. Chinese Journal of Rock Mechanics and Engineering, 2009, 28(S2), 3296(in Chinese). 祝捷, 姜耀东, 赵毅鑫.岩石力学与工程学报, 2009, 28(S2), 3296. 14 Liu H Y, Cheng Y P, Zhao C C, et al. Chinese Journal of Rock Mecha-nics and Engineering, 2010, 29(2), 358(in Chinese). 刘洪永, 程远平, 赵长春, 等.岩石力学与工程学报, 2010, 29(2), 358. 15 Wang D K, Yin G Z, Liu J, et al. ChineseJournal of Geotechnical Engineering, 2010, 32(1), 55(in Chinese). 王登科, 尹光志, 刘健, 等.岩土工程学报, 2010, 32(1), 55. 16 Brannon R M, Leelavanichkul S. International Journal of Fracture, 2010,163, 133. 17 Yu Y J, Wang D G, Li Q, et al. Journal of China Coal Society, 2012, 37(4), 585(in Chinese). 于永江, 王大国, 李强, 等.煤炭学报, 2012, 37(4), 585. 18 Hao X J, Yuan L, Lu Z G, et al. Journal of China Coal Society, 2017,42(4), 896(in Chinese). 郝宪杰, 袁亮, 卢志国, 等.煤炭学报, 2017,42(4), 896. 19 Zhao Y, Liu H. Rock Mechanics and Rock Engineering, 2012, 45, 389. 20 Sun C M, Cao S G, Li Y, et al. Journal of China University of Mining & Technology, 2016, 45(2), 244(in Chinese). 孙传猛, 曹树刚, 李勇, 等. 中国矿业大学学报, 2016, 45(2), 244. 21 Cai T T, Feng Z C, Zhao D, et al. Roil and Soil Mechanics, 2018, 39(S1), 61(in Chinese). 蔡婷婷, 冯增朝, 赵东, 等.岩土力学, 2018, 39(S1), 61. 22 Xu P, Yang S Q. Chinese Journal of Rock Mechanics and Engineering, 2015, 34(3), 537(in Chinese). 徐鹏, 杨圣奇. 岩石力学与工程学报, 2015, 34(3), 537. 23 Zhou C B, Wan Z J, Zhang Y, et al. Journal of China Coal Society, 2012, 37(12), 2020(in Chinese). 周长冰, 万志军, 张源, 等.煤炭学报, 2012, 37(12), 2020. 24 Li Z X. Damage mechanics and its application, Science Press, China, 2002(in Chinese). 李兆霞. 损伤力学及其应用, 科学出版社, 2002. 25 Lemaitre J, Chaboche J L. Mechanics of solid materials, Cambridge University Press, Cambridge, UK, 1990. 26 Huang Z P. Fundamental of continuum mechanics(2nd press), Higher Education Press, China, 2012(in Chinese). 黄筑平. 连续介质力学基础(第二版), 高等教育出版社, 2012. 27 Wu J L. Elasticity(2nd press), Higher Education Press, China, 2011(in Chinese). 吴家龙. 弹性力学(第二版), 高等教育出版社, 2011. 28 Cao W G, Zhao M H, Liu C X. Chinese Journal of Rock Mechanics and Engineering, 2005, 14(14), 2403(in Chinese). 曹文贵, 赵明华, 刘成学. 岩石力学与工程学报, 2005, 14(14), 2403. 29 Liu C X, Yang L D, Cao W G. Chinese Journal of Underground Space and Engineering, 2007, 3(3), 453 (in Chinese). 刘成学, 杨林德, 曹文贵.地下空间与工程学报, 2007, 3(3), 453. 30 Qin Q C, Li K G, Yang B W, et al. Roil and Soil Mechanics, 2018, 39(S2),14(in Chinese). 秦庆词, 李克钢, 杨宝威, 等. 岩土力学, 2018, 39(S2),14. 31 Wu Z, Zhang C J. Chinese Journal of Rock Mechanics and Engineering, 1996,15(1), 55. 吴政, 张承娟. 岩石力学与工程学报, 1996,15(1), 55. 32 Ding X, Xiao X C, Lv X F, et al. Journal of China Coal Society, 2018, 43(11), 3080(in Chinese). 丁鑫, 肖晓春, 吕祥锋, 等. 煤炭学报, 2018, 43(11), 3080. 33 Lu P, Sheng Z W, Zhu G W, et al. Journal of China University of Science and Technology, 2011, 31(6), 686(in Chinese). 卢平, 沈兆武, 朱贵旺, 等.中国科学技术大学学报, 2011, 31(6), 686. 34 Zhu J, Wang X, Yu P C, et al. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(9), 2213(in Chinese). 祝捷, 王学, 于鹏程, 等.岩石力学与工程学报, 2017, 36(9), 2213. 35 Zhao Y X, Jiang Y D. International Journal of Coal Geology, 2010, 83, 11. 36 Guo L W, Yu Q X, Jiang C L, et al. Chinese Journal of Rock Mechanics and Engineering, 2000, 19(3), 366(in Chinese). 郭立稳, 俞启香, 蒋承林, 等.岩石力学与工程学报, 2000, 19(3), 366. 37 Liu M J, Yan A H, Ding W, et al. Journal of China Coal Society, 2003, 28(1), 50(in Chinese) 刘明举, 颜爱华, 丁伟, 等. 煤炭学报, 2003, 28(1), 50. 38 Xu J, Zhou W J, Liu D, et al. Journal of China Coal Society, 2013, 38(2), 239(in Chinese). 许江, 周文杰, 刘东, 等. 煤炭学报, 2013, 38(2), 239. 39 Zhang C,Liu X F,Wang X R, et al. Journal of China Coal Society, 2018, 43(3), 743(in Chinese). 张冲, 刘晓斐, 王笑然, 等. 煤炭学报, 2018, 43(3), 743. 40 Xiao X C, Ding X, Pan Y S, et al. Roil and Soil Mechanics, 2018, 39(S2), 451(in Chinese). 肖晓春, 丁鑫, 潘一山, 等.岩土力学, 2018, 39(S2), 451. 41 冯增朝. 低渗透煤层瓦斯强化抽采理论及应用, 科学出版社, 2008.
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