Abstract:

According to the 14214 mechanized mining face actual mining production under the broken roof conditions, Combine the FLAC3D numerical calculation with theoretical analysis, Analysis the Instability Pattern of the roof of Mechanized mining head face. The studies have shown that roof of head face caving degree becomes smaller and stability enhances with the working resistance of support increases.The impact on the control of head face roof weakened with the increase of support’s working resistance when it reached more than 80% of the rated working resistance.The plastic failure area is located in the roof in front of coal wall and mainly with the form of compression and shear failure when support’s working resistance reached the rated working resistance.The front and rear pillar’s control area of roof is different if their’s working resistance ratio different.It should be raised the front pillar’s working resistance under broken roof conditions.It is conducive to the stability control of end face roof and the stability of the support when its ratio is 1:1.2.

Key words: Broken roof, roof of head face, The relationship between support and surrounding rock, working resistance