Lateral deformation characteristics of coal with bump tendency based on uniaxial compression experiment
HAO Xianjie
YUAN Liang
LI Yulin
ZHAO Yixin
ZHANG Chongfa
WANG Junzhe
GUO Yanding
ZHANG Xu
Abstract：The bump tendency and lateral deformation characteristics of 14# coal taken from Xinzhouyao coal mine were analyzed by mechanics testing system(MTS),scanning electron microscope,sonic wave testing and theoretical analysis.Results show that:1) after the peak strength of the hard coal,there is a typical step-drop,which leads to a long dynamic failure,so it is difficult to determine the bump tendency accurately by the dynamic failure time.Whereas,by elastic energy index,impact energy index and uniaxial compression strength,the coal samples can be determined as coal with strong bump tendency.2) The typical lateral deformation shows five deformation stages.At the nonlinear elastic stage,the axial deformation is larger and the lateral deformation can be ignored.At the linear elastic stage,the lateral-axial ratio gradually increases,and ultimately achieves Poisson's ratio.At the crack extension stage,the lateral deformation begins to accelerate.The stage after the peak strength has a multiple alter nate characteristic of lateral dilatation and brittle stress fall.The lateral strain increases significantly,especially when step-drop occurs.3) The increase of the lateral-axis ratio mainly happens after the peak strength,which means that the lateral expansion leads to the tensile failure,but the lateral expansion can also occur earlier at the crack propagation stage.
Keywords：bump tendencycoallateral deformationuniaxial compression
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( 129-136 )