Spatio-temporal evolution of pore and fracture structures in coal induced by initial damage and creep behavior: A real-time NMR-based approach

被引：1

作者：

Zhang, Lei ^{[1
]}

Wang, Yimeng ^{[2
]}

Gao, Mingzhong ^{[3
]}

Jia, Wenhao ^{[4
]}

Xie, Senlin ^{[2
]}

Hou, Wei ^{[2
]}

Wang, Xiangyu ^{[5
]}

Zhang, Hao ^{[1
]}

机构：

[1] College of Safety & Emergency Management Engineering, Taiyuan University of Technology, Taiyuan

[2] School of Energy and Mining Engineering, China University of Mining and Technology-Beijing, Beijing

[3] State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, Shenzhen University, Shenzhen

[4] School of Mechanics and Civil Engineering, China University of Mining and Technology-Beijing, Beijing

[5] School of Applied Science, Taiyuan University of Science and Technology, Taiyuan

来源：

International Journal of Mining Science and Technology | 2024年 / 34卷 / 10期

基金：

中国国家自然科学基金;

关键词：

Coal; Creep behavior; Fractional porosity model of seepage pores and microfractures; Initial damage; Microscopic pore and fracture structures; Nuclear magnetic resonance;

D O I：

10.1016/j.ijmst.2024.09.003

中图分类号：

学科分类号：

摘要：

Understanding the impact of mining disturbances and creep deformation on the macroscopic deformation and the microscopic pore and fracture structures (MPFS) of coal is paramount for ensuring the secure extraction of coal resources. This study conducts cyclic loading-unloading and creep experiments on coal using a low-field nuclear magnetic resonance (NMR) experimental apparatus which is equipped with mechanical loading units, enabling real-time monitoring the T2 spectrum. The experiments indicated that cyclic loading-unloading stress paths initiate internal damage within coal samples. Under identical creep stress conditions, coal samples with more initial damages had more substantial instantaneous deformation and creep deformation during the creep process. After undergoing nearly 35 h of staged creep, the total strains for coal samples CC01, CC02, and CC03 reach 2.160%, 2.261%, and 2.282%, respectively. In the creep stage, the peak area ratio of seepage pores and microfractures (SPM) gradually diminishes. A higher degree of initial damage leads to a more pronounced compaction trend in the SPM of coal samples. Considering the porosity evolution of SPM during the creep process, this study proposes a novel fractional derivative model for the porosity evolution of SPM. The efficacy of the proposed model in predicting porosity evolution of SPM is substantiated through experimental validation. Furthermore, an analysis of the impact mechanisms on key parameters in the model was carried out. © 2024

引用

页码：1409 / 1425

页数：16

共 49 条

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