Influential factors of surrounding rock deformation in goaf-side roadways based on orthogonal experiments

To identify the main controlling factors affecting the magnitude of surrounding rock deformation in gob-side entry driving, this study takes the E4102 working face of Luxin No. 2 Mine as the engineering background. Based on the orthogonal experimental design method, an L16(4⁵) orthogonal array was designed. FLAC^3D software was used to calculate the roof-to-floor convergence and two-side convergence of the roadway under 16 schemes. Range analysis and variance analysis were employed to investigate the influence of each factor on the surrounding rock deformation of the roadway. The range analysis results show that the order of influence on roof-to-floor convergence is coal pillar size > coal cohesion > main roof thickness > immediate roof thickness, while the order of influence on two-side convergence is coal pillar size > coal cohesion > immediate roof thickness > main roof thickness. The variance analysis results show that the factor with a significant influence on roof-to-floor convergence is coal pillar size, and the factors with significant influence on two-side convergence are coal pillar size and coal cohesion. Coal pillar size is the main factor controlling roadway surrounding rock deformation.