doi:10.16186/j.cnki.1673-9787.2020.2.3

Received:2019/05/18

Revised:2019/06/22

Published:2020/03/15

Experimental study on evolution law of coal-rock fracture under triaxial compression creep

WEI Guoying1,2, WANG Zehua1, JIA Tianrang1,2

1.School of Safety Science and Engineering， Henan Polytechnic University， Jiaozuo  454000 ， Henan， China;2.Research Center of the National Gas Geology and Gas Prevention Engineering， Jiaozuo  454000 ， Henan， China

Abstract:Under creep condition， the evolution law of fractures inside the coal affects the permeability of coal and gas extraction efficiency. Taking the raw coal of Zhaogu No. 2 coal mine in Jiaozuo mining area as the research object， and using the triaxial compression creep test and industrial CT scanning technology， and MATLAB software， the image equalization processing and binary image processing technology were carried out， the distribution characteristics and evolution rules of the internal fractures of coal samples under different loading conditions were studied. The results showed ： the internal fracture distribution of coal sample was controlled by the main fracture and was unevenly ； with the increase of loading and extension of loading time， the percentage of the internal fracture volume increased in the coal sample. The fracture widened and also gradually penetrated the coal sample. There were several new secondary fractures near the main fracture， and the main fracture was connected by the cross fractures. The direction of fracture development of coal-rock mass was mainly along the direction of its axial stress or extending with a small degree of the angle ； the development of fractures mainly was the first failure of micro-fractures， and the stress concentration promoted the development of large fractures. Therefore， the conclusion laid a foundation for the gas flow rule of coal-mass around the gas extraction boreholes and the determination of their influence range.

Key words:coal rock;creep;triaxial loading;fracture evolution;computed tomography scan

三轴压缩蠕变条件下煤岩裂隙演化规律试验研究_魏国营.pdf