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Optimization study on roof break direction of gob-side entry retaining by roof break and filling in thick-layer soft rock layer.

Authors :
Dang-Wei Yang
Zhan-Guo Ma
Fu-Zhou Qi
Peng Gong
Dao-Ping Liu
Guo-Zhen Zhao
Ray Ruichong Zhang
Source :
Geomechanics & Engineering (2005-307X). Aug2017, Vol. 13 Issue 2, p195-215. 21p.
Publication Year :
2017

Abstract

This paper proposes gob-side entry retaining by roof break and filling in thick-layer soft rock conditions based on the thick-layer soft rock roof strata migration law and the demand for non-pillar gob-side entry retaining projects. The functional expressions of main roof subsidence are derived for three break roof direction conditions: lateral deflection toward the roadway, lateral deflection toward the gob and vertically to the roof. These are derived according to the load-bearing boundary conditions of the main roadway roof stratum. It is concluded that the break roof angle is an important factor influencing tire stability of gob-side entry retaining surrounding rock. This paper studies the stress distribution characteristics and plastic damage scope of gob-side entry retaining integrated coal seams, as well as the roof strata migration law and tire supporting stability of caving structure filled on tire break roof layer at the break roof angles of -5°, 0°, 5°, 10° and 15° are studied. The simulation results of numerical analysis indicate that the stress concentration and plastic damage scope to tire sides of gob-side entry retaining integrated coal at the break roof angle of 5° are reduced and shearing stress concentration of the caving filling body has been eliminated. The disturbance of coal raining to tire roadway roof and loss of canying capacity are mitigated. Field tests have been earned out on air-retum roadway 5203 with the break roof angle of 5°. lire monitoring indicates that tire break roof filling section and compaction section are located at 0-45 nr and 45-75 m behind the working face, respectively. Tire section from 75-100 nr tends to be stable. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
2005307X
Volume :
13
Issue :
2
Database :
Academic Search Index
Journal :
Geomechanics & Engineering (2005-307X)
Publication Type :
Academic Journal
Accession number :
124910328
Full Text :
https://doi.org/10.12989/gae.2017.13.2.195