Study on deformation characteristics of surrounding rock of roof cutting and pressure relief in gob-side entry retaining of top coal caving
Hu Junfeng
Lü Yuzhu
Jing Yongjia
Wu Jie
Liu Xinmin
Li Junqi
Abstract：Fully-mechanized top coal caving with gob-side entry retaining differs from traditional gob-side entry retaining technology for thin coal seams.The greater thickness of the top coal caving seam results in more severe deformation of roadway roof and floor,as well as the coal ribs.The pressure on the retained roadway can be effectively alleviated by roof cutting and pressure relief.Taking the No.3309 fully-mechanized top coal caving face in Sangshuping No.2 mine of Hancheng Mining Area as the engineering background,the displace-ment variation characteristics of roof after cutting and pressure relief were theoretically analyzed and demonstrated.The optimal cutting height was calculated to be 8 meters.Furthermore,by utilizing numerical simulation software,the stress-displacement variation laws of the roadway roof,floor,and coal rib after cutting were analyzed.The results indicate that the roof cutting and pressure relief technique has a-chieved remarkable effects.The stress concentration phenomenon on the goaf side of roadway has been effectively relieved.The peak stress has decreased by 16.6％compared to the situation without roof cutting,and the subsidence of adjacent roof has reduced by 28.6％,which is align well with theoretical calculation data.After adopting the roof cutting and pressure relief technology for the gob-side entry retaining roof,the stress environment has been improved,and the displacement of the surrounding rock in the entry has been significantly reduced.
Keywords：gob-side entry retainingblasting and roof cuttingdisplacement variationstress distributionnumerical simulation
Publication Date：2025-12-30
Online Publishing Date：2026-01-31(First online date of this platform, not the publication date of the document)
Pages：8( 85-91,97 )