Study on Relationship Between Initial Support Force of Hydraulic Powered Support and Mine Strata Pressure Behavior of Coal Mining Face

According to the low initial support force problem occurred in the powered supports jammed accident in the Yousanpian coal mining face of Tiebei Mine, with the applications of the site measurement, theoretical analysis and other means, the initial support force of the 60% powered supports measured at the coal mining f ace was lower than 3 000 kN and the influence relationship of the powered support's initial support to the roof subsidence value, the working resistance of the powered support and the dynamic coefficient was analyzed.The study showed that the initial support force of the powered support would have an important role to control the sta bility of the direct roof and to reduce the failure degree of the roof.The low initial support force could cause an early separation and broken of the roof and the high initial support force could be favorable to fully play the performances of the powered support and could ensure the safety operation and high efficient production.