Calculation for Leaving Reasonabe Safety Coal Pillar in Seam Excavation Roadway Along Goaf

In the process of construction design for coal mine merging and reorganization, in order to better meet the requirements of safe and efficient production, we need to arrange seam excavation roadway along goaf or minitype coal mine breaking area. Through the analysis of breaking features of goaf roadway surrounding rock, according to the real failure of coal mass around goaf, we find out that the insufficient of calculation formula in coal pillar design. Based on the theory of loose circle, we revise the calculation formula, and propose a simple calculation formula to solve the status which is lack of theory basis in goaf roadway safety coal pillar design of Shanxi Province resource integration mines.