Citation

Li G, Zhao G, Meng X, Peng R, Cheng X, Yu T. China Saf. Sci. J. 2019; 29(2): 125-132.

Copyright

(Copyright © 2019, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2019.02.021

PMID

unavailable

Abstract

In order to reasonably design supporting parameters of the fully-mechanized caving roadway along gob subject to dynamic pressure, the gob-side transportation entry of 9102 working face of Hengsheng colliery was taken as an example, the fracture development and deformation characteristics of roadway were observed by using borehole peeper and multi-point displacement meter. FLAC3D was used to simulate the distribution characteristics of support stress field in surrounding rock when the roadway adopted different supporting parameters of bolts and cables, and the coupling coefficient of compressive stress zone is defined to evaluate the coupling performance of bolts and cables. On this basis, the support parameters were optimized, and FLAC3D was used to simulate and compare the deviatoric stress and displacement distribution characteristics of surrounding rock when using the original and optimizing supporting schemes, then field tests were carried out. The results show that reducing the spacing between cables, increasing the length and pretension of the cable can form an effective and continuous compressive stress concentration area in the surrounding rock, that when the coupling coefficient of the compressive stress area is greater than 1. 4, the height of compressive stress concentration area is higher than the thickness of top coal, that when the length of the cable is 8 m, the stratum, in which the anchoring section of the cable is located, has low deviatoric stress, which improves the reliability of the bolt-net-anchor coupling supporting system, and that both the roof abscission layer and large deformation of surrounding rock can be controlled basically when the support parameters are optimized, which guarantees the safety of gob-side entry. © 2019 China Safety Science Journal. All rights reserved.

Language: zh