Comparative research on mechanical properties of coal specimens and coal mass based on Hoek-Brown criterion
HAN Ying
ZHAO Qianfu
ZHANG Feiyan
Abstract：In order to discuss the mechanical property differences between raw coal and shaped coal,and whether shaped coal can be used to replace the raw coal to estimate its mechanical parameters.In this paper,the property differences of strength,deformation and failure for raw coal and shaped coal were studied with uniaxial compression,conventional triaxial compression tests by using RMT-150C rock mechanics test system.The undetermined parameter of H-B strength criterion were fitted to the test data with least square method,and the value of coal mass mechanical parameters estimated by raw coal were compared to by shaped coal.Results show that the uniaxial compressive strength of coal specimens shaped by 200 kN steady voltage is roughly 1/3 that of the raw coal specimen;the fracture of raw coal specimen is mainly splitting failure along axial occurred in uniaxial compression experiment,while the shaped coal failure mode is mainly spalling from both ends like a cone,finally unstable failure occurred in middle of coal specimen.The cohesion and internal friction angle of coal mass estimated by raw coal basically consistent with that by shaped coal.For soft coal,it can be used shaped coal instead of raw coal to estimate cohesion and internal friction of coal mass.
Keywords：raw coalshaped coalcoal masscohesioninternal friction angle
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 23-30 )