Mechanical properties of coal and rock mass under thermo-mechanical coupling

  • Jun Deng
  • Shuai-Jing RenEmail author
  • Yang XiaoEmail author
  • Chi-Min Shu
Part of the following topical collections:
  1. Mine Safety Science and Engineering


The properties of coal and rock mass in coalfield fire areas require investigation because both coal and rock can become deformed by impact or under high temperatures. Thermo-mechanical coupling forms interconnected channels in the air and can produce a combustion center along a coal seam which can further promote unwanted spontaneous combustion. This paper uses a MTS880/25T electro-hydraulic servo material test system to conduct uniaxial compression experimental tests on coal and rock samples from Huojitu coal mine located in Yulin City, Shaanxi Province, China. Various mechanical parameters were recorded for the samples at different temperatures. Results indicate that temperature has a significant effect on the strength of coal and rock mass. As temperature increased, peak strain, elastic modulus, and peak stress of coal and rock mass decreased at first, then rose, and eventually decreased. From 25 to 200 °C, the elastic modulus and peak stress of the rock samples gradually decreased with an increase in temperature, showing a decrease of 31.45% and 34.07%, respectively. Above 200 °C, they gradually rose to their maximum and promptly dropped until the temperature exceeded 400 °C. Peak strain of the rock samples was slightly different from the elastic modulus and peak stress in the same temperature stage. At 300 °C, peak strain increased to its maximum value. Above 300 °C, peak strain began to drop. The peak strain, elastic modulus, and peak stress of the coal sample were less affected by temperatures below 100 °C. They gradually increased until temperatures exceeded 100 °C. The maximal values for peak strain, elastic modulus, and peak stress corresponded to temperatures of 140, 200, and 200 °C, respectively. After the temperatures corresponding to the maximal values were exceeded, the peak strain, elastic modulus, and peak stress of the coal samples decreased.


Coalfield fire Uniaxial compression Peak strain Elastic modulus Peak stress 



We would like to express our heartfelt gratitude to Jing-Yu Zhao, Cai-Ping Wang, Yan-Ni Zhang, and Kai Wang, who have given the helpful assistance and guidance in preparing this manuscript.

Funding information

This work was supported by the International Science and Technology Cooperation and Exchange of Shaanxi Province (No. 2016KW-070), the China Postdoctoral Science Foundation (No. 2016M590963), and the Industrial Science and Technology Project of Shaanxi Province, China (No. 2016GY192).


  1. Al-Shayea NA, Khan K, Abduljauwad SN (2000) Effects of confining pressure and temperature on mixed-mode (I–II) fracture toughness of a limestone rock. Int J Rock Mech Min Sci 37(4):629–643Google Scholar
  2. Cai MF, Qiao L, Yu B, Wang SH (1999) Results and analysis of in-situ stress measurement at deep position of no. 2 mining area of Jinchuan Nichkel mine. Chin J Rock Mech Eng 18(4):414–418Google Scholar
  3. Chen G, Ma XQ, Lin MS, Lin YS, Yu ZS (2015) Study on thermochemical kinetic characteristics and interaction during low-temperature oxidation of blended coals. J Energy Inst 88(3):221–228Google Scholar
  4. Choi H, Jo W, Kim S, Yoo J, Chun D, Rhim Y, Lim J, Lee S (2014) Comparison of spontaneous combustion susceptibility of coal dried by different processes from low-rank coal. Korean J Chem Eng 31(12):2151–2156Google Scholar
  5. Deng J, Zhao JY, Huang AC, Zhang YN, Wang CP, Shu CM (2017) Thermal behavior and microcharacterization analysis of second-oxidized coal. J Therm Anal Calorim 127(1):439–448Google Scholar
  6. Friedman M, Perkins RD, Green SJ (1969) Observation of brittle-deformation features at maximum stress of westly granite and solenhofen limeston. Int J Rock Mech Min Sci 50(4):757–766Google Scholar
  7. Hao Y, Zhang ZY, Liao H, Wei YM (2015) China’s farewell to coal: a forecast of coal consumption through 2020. Energy Policy 86:444–455Google Scholar
  8. Hao Y, Liu Y, Weng JH, Gao Y (2016) Does the environmental Kuznets curve for coal consumption in China exist? New evidence from spatial econometric analysis. Energy 114:1214–1223Google Scholar
  9. He MC (2004) Present situation and prospect of rock mechanics in deep mining engineering. Chin J Rock Mech Eng:88–94Google Scholar
  10. He MC, Lv XJ, Jing HH (2002) Characters of surrounding rockmass in deep engineering and its non-linear dynamic-mechanical design concept. Chin J Rock Mech Eng 21(8):1215–1224Google Scholar
  11. Hudson JA (1971) Shape of the complete stress-strain curve for rock. Proc 13th, Symp on Rock Mech 111Google Scholar
  12. Jiang B, Qin Y, Jin FL (1998) Deformation characteristics of super-microstructures of coal under the condition of high temperature and confining pressure. Chin J Geol 33(1):18–25Google Scholar
  13. Jo W, Choi H, Kim S, Yoo J, Chun D, Rhim Y, Lim J, Lee S (2015) Changes in spontaneous combustion characteristics of low-rank coal through pre-oxidation at low temperatures. Korean J Chem Eng 32(2):255–260Google Scholar
  14. Li XS (2008) Experimental study on mechanical properties of grit stone after high temperature. Henan Polytechnic University, JiaozuoGoogle Scholar
  15. Liu S, Xu J (2015) An experimental study on the physico-mechanical properties of two post-high-temperature rocks. Eng Geol 185:63–70Google Scholar
  16. Liu YK, Cao P, Yi YL, Zhang XY, Chen R (2010) Revised RMR system on underground deep engineering rock mass property. J Cent S Univ (Sci Technol) 41(4):1497–1505Google Scholar
  17. Lv ZX, Feng ZC, Zhao YS (2007) Influence of rock inhomogeneity on strength-size effect of rock materials. J China Coal Soc 32(9):917–920Google Scholar
  18. Ma ZG, Mao XB, Li YS, Chen ZQ, Zhu P (2005) Experimental study on the effect of temperature on mechanical properties of coal. Ground Pressure Strata Control 03:46–48Google Scholar
  19. Mahmutoğlu Y (2006) The effects of strain rate and saturation on a micro-cracked marble. Eng Geol 82(3):137–144Google Scholar
  20. Meng ZP, Li MS, Lu PQ, Tian JQ, Lei Y (2006) Temperature and pressure under deep conditions and their influences on mechanical properties of sandstone. Chin J Rock Mech Eng 25(6):1177–1181Google Scholar
  21. Okubo S, Nishimatsu Y (1985) Uniaxial compression testing using a linear combination of stress and strain as the control variable. Int J Rock Mech Min Sci Geomech Abstr 22(5):323–330Google Scholar
  22. Okubo S, Nishimatsu Y, He C (1990) Loading rate dependence of class II rock behaviour in uniaxial and triaxial compression tests—an application of a proposed new control method. Int J Rock Mech Min Sci Geomech Abstr 27(6):559–562Google Scholar
  23. Pec M, Stünitz H, Heilbronner R (2012) Semi-brittle deformation of granitoid gouges in shear experiments at elevated pressures and temperatures. J Struct Geol 38:200–221Google Scholar
  24. Sang CB (2016) Research on assessment and prediction about typical harmful gas pollution at coal fire area. Xi’an University of Science and Technology, Xi’anGoogle Scholar
  25. Sang HC, Ogata Y, Kaneko K (2003) Strain-rate dependency of the dynamic tensile strength of rock. Int J Rock Mech Min Sci 40(5):763–777Google Scholar
  26. Stracher GB, Taylor TP (2004) Coal fires burning out of control around the world: thermodynamic recipe for environmental catastrophe. Int J Coal Geol 59(1–2):7–17Google Scholar
  27. Teng SR (2007) Structure study based on the discovery in Huojitu well field. Liaoning Technol University, FuxinGoogle Scholar
  28. Wang GL (2002) Research on mine pressure and overlying strata movement in the first coalface of the Huojitu mine. Liaoning Technology University, FuxinGoogle Scholar
  29. Wang JL (2006) Research on mining coal bed spontaneous combustion and prevention basic of Shendong mining area. Liaoning Technology University, FuxinGoogle Scholar
  30. Wang ZK (2017) Petrologic studies on mechanical properties of sedimentary rocks of Jurassic coal measures in Shendong. Henan Polytechnic University, JiaozuoGoogle Scholar
  31. Wong TF (1982) Micromechanics of faulting in westerly granite. Int J Rock Mech Min Sci Geomech Abstr 19(2):49–64Google Scholar
  32. Xu XC, Liu QS (2000) A preliminary study on basic mechanical properties for granite at high temperature. Chin J Geotech Eng 22(3):332–335Google Scholar
  33. Xu J, Zhou M, Li H (2018) The drag effect of coal consumption on economic growth in China during 1953–2013. Resour Conserv Recycl 129:326–332Google Scholar
  34. Yamabe T, Neaupane KM (2001) Determination of some thermo-mechanical properties of Sirahama sandstone under subzero temperature condition. Int J Rock Mech Min Sci 38(7):1029–1034Google Scholar
  35. Yan WC, Gao YN, Wang ZK (2018) Analysis of strength and brittleness of coal and rock under influence of temperature–confining pressure–gas. Coal Technol 37(2):167–169Google Scholar
  36. Yin TB (2012) Study on dynamic behaviors of rocks considering thermal effect. Central South University, ChangshaGoogle Scholar
  37. Yin HY (2013) Research on the effect of thermal-mechanical coupling of hard rock mechanical behaviors and the mechanism rockburst. Chengdu University of Technology, ChengduGoogle Scholar
  38. Yuan M, Li BB, Du YQ, Meng QH, Xu SQ (2015) Experimental research on influence of temperature on mechanical properties of coal containing gas. Safety in Coal Mines 46(11):6–9Google Scholar
  39. Zhang ZX, Kou SQ, Jiang LG, Lindqvist PA (2000) Effects of loading rate on rock fracture: fracture characteristics and energy partitioning. Int J Rock Mech Min Sci 37(5):745–762Google Scholar
  40. Zhang HQ, Xu JF, He YN, Han LJ, Jiang BS, Shao P (2012) Study of laboratory scale effect of limestone under uniaxial compression. Chin J Rock Mech Eng 31(2):3491–3496Google Scholar
  41. Zhao Y, Wan Z, Feng Z, Yang D, Zhang Y, Qu F (2012) Triaxial compression system for rock testing under high temperature and high pressure. Int J Rock Mech Min Sci 52:132–138Google Scholar
  42. Zhou HW, Xie HP, Zuo JP (2005) Developments in researches on mechanical behaviors of rocks under the condition of high ground pressure in the depths. Adv Mech 35(1):91–99Google Scholar

Copyright information

© Saudi Society for Geosciences 2019

Authors and Affiliations

  1. 1.School of Safety Science and EngineeringXi’an University of Science and TechnologyXi’anPeople’s Republic of China
  2. 2.Shaanxi Key Laboratory of Prevention and Control of Coal FireXi’anPeople’s Republic of China
  3. 3.Graduate School of Engineering Science and TechnologyNational Yunlin University of Science and TechnologyDouliouTaiwan, Republic of China

Personalised recommendations