Double Roadway Deformation Characters Under Coal Pillar with Many Mining and in Shallow

To many mining process problems of double roadways as upper and lower coal seam synchronous mining under wide coal pillar of Huojitu mine，field test and numerical simulation was applied，and the double roadways deformation characters under 35m width coal pillar was studied.The results showed that the total deformation amount between roof to floor of roadway would reached 201mm，which under coal pillar after upper coal seam working face mining，roadway deformation speed began accelerate at advanced 15m of working face，but the deformation amount that roadway influenced by lower coal seam under coal pillar than upper coal seam.The field test showed roadway deformation speed accelerate at the position 15～30m to working face after four mining influence，the final roof to floor sag increased only 32mm，and two sides convergence increased only 24mm，roadway deformation amount minimum，it could guaranteed for mine safety and production high efficiency，and references for similar situation.