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Geomechanics and Engineering
  Volume 23, Number 6, December25 2020, pages 503-512
DOI: http://dx.doi.org/10.12989/gae.2020.23.6.503
 


Thermographic analysis of failure for different rock types under uniaxial loading
Alper Kirmaci and Mustafa Erkayaoglu

 
Abstract
    Mining activities focus on the production of mineral resources for energy generation and raw material requirements worldwide and it is a known fact that shallow reserves become scarce. For this reason, exploration of new resources proceeds consistently to meet the increasing energy and raw material demand of industrial activities. Rock mechanics has a vital role in underground mining and surface mining. Devices and instruments used in laboratory testing to determine rock mechanics related parameters might have limited sensing capability of the failure behavior. However, methodologies such as, thermal cameras, digital speckle correlation method and acoustic emission might enable to investigate the initial crack formation in detail. Regarding this, in this study, thermographic analysis was performed to analyze the failure behaviors of different types of rock specimens during uniaxial compressive strength experiments. The energy dissipation profiles of different types of rocks were characterized by the temperature difference recorded with an infrared thermal camera during experiments. The temperature increase at the failure moment was detected as 4.45oC and 9.58oC for andesite and gneiss-schist specimens, respectively. Higher temperature increase was observed with respect to higher UCS value. Besides, a temperature decreases of about 0.5-0.6oC was recorded during the experiments of the marble specimens. The temperature change on the specimen is related to release of radiation energy. As a result of the porosity tests, it was observed that increase in the porosity rate from 5.65% to 20.97% can be associated to higher radiation energy released, from 12.68 kJ to 297.18 kJ.
 
Key Words
    failure; laboratory analysis; rock; stress-strain relations; energy geomechanics
 
Address
Alper Kirmaci and Mustafa Erkayaoglu: Department of Mining Engineering, Middle East Technical University,
Universiteler Mahallesi, Dumlupinar Bulvari No:1, 06800 Çankaya/Ankara, Turkey
 

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