The Infrared Radiation Characteristics of Sandstone Fracture Seepage under Coupled Stress-Hydro Effect

Abstract

Effective monitoring of rock fracture and seepage is an important information means to ensure the safety of geotechnical engineering. Therefore, sandstone samples were subject to uniaxial compression under different hydraulic conditions in the presence of infrared radiation and observation. This study uses the multiple infrared radiation indexes (ΔAIRT, IRV, VDIIT) and image data to analyze the influence of coupled stress-hydro effect of infrared radiation change on sandstone surface. The main findings are: (1) The surface temperature of sandstone samples rises in the compaction and linear elastic stages, keeps stable or decreases in the fracture development stage, and rapidly decreases in the post-peak failure stage. (2) The samples with internal water pressure not more than 0.30 MPa, surface temperature and load curve at the compaction and linear elastic stage have a strong power function relationship, which a coefficient of determination is 0.8900. (3) The IRV curve appears as a pulse jump at the time of water seepage. After that, both the fracture development and the post-peak failure stages have stepped up. The VDIIT curve also appears to be a pulse jump at the time of water seepage, and obvious up and down fluctuations exist before water seepage and fracture. (4) Based on the Pauta Criterion, by analyzing the values of VDIIT during the experiment, the early warning threshold of sandstone fracture seepage is determined to be 0.00559. The research finding can provide an experimental and theoretical basis for the early warning of flood accidents in underground rock engineering.

Assessing the Performance of CO2-Mineralized Underground Backfilling Materials through the Variation Characteristics of Infrared Radiation Temperature Index

“…Sun et al utilized infrared and acoustic emission combined monitoring to investigate the thermo-acoustic effects during the rock damage process, and the results showed that the VSMIT and the related dimension of the acoustic emission ringing count (Dm) exhibit significant mutation during rock damage and fracture events, with the VSMIT mutation time being earlier than the Dm mutation time in 71.1% of rock samples, indicating that the formation of unstable cracks is the fundamental reason for the mutation in the VSMIT and Dm [45]. Cui et al utilized an infrared thermal camera to monitor sandstone water seepage experiments, and the results revealed a significant mutation in the VOIIT and VSMIT before the sandstone water seepage fracture, with the VSMIT exhibiting pulse-like mutation [46].…”

“…Therefore, the VSMIT is more advantageous for identifying the infrared radiation precursors of bearing coal and rock failure, making it easier to capture the precursors of bearing coal and rock failure. Therefore, the VSMIT is suitable as an indicator for searching for precursors of bearing coal and rock failure [46].…”

“…At the same time, based on the actual situation on site, the AIRT threshold of the #15 coal seam was set to 0.5 °C and the VSMIT threshold was set to 0.005532. According to the infrared indicator threshold, any place exceeding the threshold can be determined as the location of coal rock fracture and seepage water, thus determining the high-risk area for water inrush disasters [52].…”

Infrared Precursor Experiment to Predict Water Inrushes in Underground Spaces Using a Multiparameter Normalization

“…Under high hydraulic gradients, weak permeable areas form and extend, leading to soil water slurry explosions [10][11][12][13]. The infrared radiation information of rock changes during the process of stress redistribution and consequent fracture damage process [14][15][16][17][18][19][20]. Monitoring the infrared radiation released to the outside during the process of rock loading can predict the characteristics and process of rock deformation and failure.…”