Mechanical analysis of floor deformation and floor heave control technology for gob-side entry retaining in medium thick coal seam with shallow cover depth

Gob-side entry retaining technology is of great significance to improve coal recovery rate, improve roadway stress environment and ensure mine safety and efficiency. In order to solve the problem of floor heave deformation of gob-side entry retaining in shallow coal seam, based on the engineering background of 12407 and 12408 fully mechanized mining face in Wulanmulun Coal Mine, the concept of equivalent load is introduced based on the roof load strip segmentation method, and the equivalent load distribution model of gob-side entry retaining floor is established. The mechanical analysis of gob-side entry retaining floor is carried out and the maximum floor heave of roadway floor is calculated. FLAC3D numerical calculation method is used to analyze the main control factors of floor heave deformation of gob-side entry retaining. The numerical simulation results show that the strength difference between roadside filling body and isolated coal pillar leads to asymmetric deformation of roadway floor, and under the