RESEARCH ON MECHANICAL PROPERTIES AND ACOUSTIC EMISSION CHARACTERISTICS OF ROCK BEAMS WITH DIFFERENT LITHOLOGIES AND THICKNESSES

Authors

  • TONG-BIN ZHAO College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao 266590, China and State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao https://orcid.org/0000-0003-2017-7244
  • PENG-FEI ZHANG College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao 266590, China and b State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao 266590, China https://orcid.org/0000-0002-1976-5914
  • WEI-YAO GUO College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao 266590, China and b State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao 266590, China https://orcid.org/0000-0003-3589-4537
  • YA-XUN XIAO State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071, China https://orcid.org/0000-0002-5771-6187
  • YONG-QIANG ZHAO State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, Beijing 102209, China https://orcid.org/0000-0001-8823-1003
  • XIANG SUN Shandong Energy Group Co., Ltd., Jinan 250014, China https://orcid.org/0000-0003-0899-8584

DOI:

https://doi.org/10.1590/1679-78256711

Abstract

THE LITHOLOGY AND THICKNESS OF THE ROCK BEAM AFFECT ITS MECHANICAL PROPERTIES AND ACOUSTIC EMISSION CHARACTERISTICS WHEN IT IS FRACTURED. IN THIS STUDY, THREE-POINT BENDING TESTS OF ROCK BEAMS WERE CARRIED OUT. THEN, WE PROPOSED TO UTILIZE THE PERCENTAGE OF PEAK ENERGY TO CHARACTERIZE THE INTENSITY OF ENERGY RELEASE DURING FRACTURE. FINALLY, THE ENERGY RELEASE MECHANISM OF COAL ROOF FRACTURE WAS DISCUSSED. THE EVOLUTION PROCESS OF ACOUSTIC EMISSION INCLUDES FIVE STAGES. THE ACOUSTIC EMISSION AMPLITUDE DISTRIBUTION OF ROCK BEAMS HAS THREE TYPICAL PATTERNS. MOST OF THE CRACKS AFTER FRACTURE ARE TENSILE CRACKS, THE PROPORTION OF TENSILE CRACKS IS POSITIVELY CORRELATED WITH THE ELASTIC MODULUS. THE PERCENTAGE OF PEAK ENERGY IS POSITIVELY CORRELATED WITH THICKNESS AND ELASTIC MODULUS. MORE ENERGY IS RELEASED WHEN THICK AND HARD ROOF FRACTURES. WHEN NECESSARY, MEASURES SUCH AS REDUCING THE THICKNESS OR THE STRENGTH OF THE ROOF COULD BE TAKEN TO IMPROVE THE SAFETY OF MINING.

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Published

2021-10-26

Issue

Vol. 18 No. 8 (2021)

Section

Articles

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