Study on mine strata pressure behavior law of irregular fully-mechanized top coal caving mining face in seam with shallow depth

In order to have the mine strata pressure behavior,mine gateway deformation and advance stress distribution law occurred in the fully mechanized top coal caving mining process of No.6204 Abnormal Coal Mining Face in Yangwangou Mine,with several monitoring and measuring means and the detection means,a study of the mine strata pressure behavior law was conducted on the irregular fully mechanized top coal caving mining face. The study results showed that the roof weighting step dista nce of the irregular coal mining face was related to the length of the open-off cut. The longer of the open-off cut was,the shorter of roof weighting step distance would be an d the roof weighting strength would be getting lower and vice versa. During the pushing forward period of the coal mining face,the deformation of the mine gateway was sm all. Even at the period of the initial roof weighting and periodical roof weighting, the deformation of the mine gateway was not obviously increased. Meanwhile,with the data analysis,the advance influence scope of the support pressure in the coal mining face provided was 5 m and after over 5 m,the advance support pressure of the coal mining face would be small in variation. The seismic wave velocity CT detection also showed that there was a stress concentrated zone existed at a distance of0 ~ 20 m to the Co al mining face.