Study on roof pressure- relief mechanism and application technology of large cross section chamber

In order to keep long stability of deep chamber,reduce the maintenance cost of chamber and ensure the safety production of mine,take the second large par t cross section drive head chamber in blind shaft of Xinzhuang Mine as engineering background,numerical calculation was applied to study pressure- relief mechanism of「 oof pressure- relief roadway for large cross section chamber. The study results showed that after roof pressure- relief,the plumb stress of surrounding rock in roof and floor of chamber was sharply reduced both,but the plumb stress of floor was reduced sharplyer than roof. The roof pressure- relief would have less interference to roof of chamb er.After pressure- relief,the horizontal stress and horizontal displacement of roof, floor and two sides surrounding rock of chamber were obviously reduced and therefore pre ssure- relief effect of roof was obvious. Based on these,the parameters of roof pressure- relief roadway and pressure- relief area of large cross section chamber were desig ned. After pressure- relief roadway driven,directional throw blasting method was applied to the construction method of roof pressure- relief area.