矿业科学技术学报(英文版)2024，Vol.34Issue(1) ：77-90.DOI:10.1016/j.ijmst.2023.12.001

Pore-pressure and stress-coupled creep behavior in deep coal:Insights from real-time NMR analysis

Wenhao Jia Hongwei Zhou Senlin Xie Yimeng Wang Xinfeng Hu Lei Zhang
矿业科学技术学报(英文版)2024，Vol.34Issue(1) ：77-90.DOI:10.1016/j.ijmst.2023.12.001
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  • 维普
  • 万方数据

Pore-pressure and stress-coupled creep behavior in deep coal:Insights from real-time NMR analysis

Wenhao Jia 1Hongwei Zhou 2Senlin Xie 3Yimeng Wang 3Xinfeng Hu 1Lei Zhang4
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作者信息

  • 1. School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China
  • 2. School of Energy and Mining Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology-Beijing,Beijing 100083,China
  • 3. School of Energy and Mining Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China
  • 4. College of Safety and Emergency Management Engineering,Taiyuan University of Technology,Taiyuan 030024,China
  • 折叠

Abstract

Understanding the variations in microscopic pore-fracture structures(MPFS)during coal creep under pore pressure and stress coupling is crucial for coal mining and effective gas treatment.In this manu-script,a triaxial creep test on deep coal at various pore pressures using a test system that combines in-situ mechanical loading with real-time nuclear magnetic resonance(NMR)detection was conducted.Full-scale quantitative characterization,online real-time detection,and visualization of MPFS during coal creep influenced by pore pressure and stress coupling were performed using NMR and NMR imaging(NMRI)techniques.The results revealed that seepage pores and microfractures(SPM)undergo the most significant changes during coal creep,with creep failure gradually expanding from dense primary pore fractures.Pore pressure presence promotes MPFS development primarily by inhibiting SPM compression and encouraging adsorption pores(AP)to evolve into SPM.Coal enters the accelerated creep stage earlier at lower stress levels,resulting in more pronounced creep deformation.The connection between the micro and macro values was established,demonstrating that increased porosity at different pore pres-sures leads to a negative exponential decay of the viscosity coefficient.The Newton dashpot in the ideal viscoplastic body and the Burgers model was improved using NMR experimental results,and a creep model that considers pore pressure and stress coupling using variable-order fractional operators was developed.The model's reasonableness was confirmed using creep experimental data.The damage-state adjustment factors ω and β were identified through a parameter sensitivity analysis to characterize the effect of pore pressure and stress coupling on the creep damage characteristics(size and degree of difficulty)of coal.

Key words

Real-time monitoring/Pore pressure-stress coupling/Microscopic pore-fracture structure/Variable-order fractional creep model/Deep coal

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基金项目

National Natural Science Foundation of China(52121003)

National Natural Science Foundation of China(51827901)

National Natural Science Foundation of China(52204110)

China Postdoctoral Science Foundation(2022M722346)

111 Project(B14006)

Yueqi Outstanding Scholar Program of CUMTB(2017A03)

出版年

2024
矿业科学技术学报(英文版)
中国矿业大学

矿业科学技术学报(英文版)

CSTPCDCSCDEI
影响因子：1.222
ISSN：2095-2686
参考文献量69
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