Shuaifeng Yin

Abstract To address the problem of large-scale deformation failure caused by stress concentration in gob-side entry retainment under thick and hard roof conditions, this study takes the return airway of the 9303 working face at Hengsheng Coal Mine as the engineering background. Through field measurements, theoretical calculations, and numerical simulations, the asymmetric instability mechanism of the gob-side entry under a thick and hard roof was determined.

1 Introduction In China's coal mining industry, roadway support [1-3] is an effective and reliable method; it is a prerequisite for all mining operations and essential for the safe and smooth progress of coal mine construction and production. With the deepening and intensification of coal mining, the enlargement of roadway cross-sections [4], and the intense impact of mining operations, the difficulty of roadway support has increased significantly, presenting numerous challenges.

1 Introduction As coal mining in China extends into deeper strata and more complex geological conditions, mining intensity continues to increase, with working face layouts becoming increasingly compact. When employing the longwall mining method along strike, the rational retention of sectional pillars and the stability control of their internal roadways represent core technical challenges for ensuring safe and efficient mine production [1-3].