Macro-and micro-mechanical response and damage mechanism of sandstone under high-temperature conditions  

作　　者：Laiwei Wu Yanli Huang Junmeng Li Guiyuan Wang Yingshun Li Xiaotong Li Junzhi Chen Chuning Ji 

机构地区：[1]State Key Laboratory of Coal Exploration and Intelligent Mining,School of Mines,China University of Mining and Technology,Xuzhou 221116,China [2]Key Laboratory of Xinjiang Coal Resources Green Mining,Ministry of Education,Xinjiang Institute of Engineering,Urumqi 830023,China

出　　处：《International Journal of Mining Science and Technology》2025年第2期265-274,共10页矿业科学技术学报(英文版)

基　　金：supported by the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project (No. 2024ZD1004104);the Xinjiang Key Research and DevelopmentSpecialProject(Nos.2023B03009-1and 2022B03028-3);the National Natural Science Foundation of China (Nos. 52104103, 52174128, and 52364021);the Teaching Research Project of China University of Mining and Technology (No. 2024JY013)。

摘　　要：The thermal effects of coal combustion considerably influence the physical and chemical properties,structural characteristics, and stability of rocks, posing a serious threat to the safety of coal mining operations. In this study, the impacts of temperature on the physical and chemical characteristics(i.e., mineral phase, microstructure, and mechanical strength) of sandstone were investigated by employing experimental methods, including microstructural analysis, uniaxial acoustic emission(AE), and nuclear magnetic resonance(NMR). The results indicate that temperature alters the mineral phase and the pore characteristics, and these two factors jointly affect the mechanical properties of sandstone. The influence of temperature on the mechanical strength of sandstone is categorized into low-temperature strengthening and high-temperature damage, with a threshold temperature identified at 600 ℃. The lowtemperature strengthening effect encompasses both pore strengthening and mineral phase strengthening, while the high-temperature damage effect primarily results from pore damage. As the experimental temperature rises, both the number of AE events and the AE energy transition from a surge in the postpeak failure stage to a stepwise increase during the loading process. This transition implies that the failure mode of the sandstone sample evolves from brittle failure to tensile failure.

关 键 词：Thermal effects Mineral phase Pore structure Acoustic emission energy Microscopic morphology 

分 类 号：TD315[矿业工程—矿井建设]