Analysis on Strata Pressure Features of Mining Face Under Conditions of Fully Mechanized Coal Mining and Fully Mechanized Top Coal Caving Mining

Based on the same roof conditions,the differences of the average mine pressure behavior between the fully mechanized coal mining and the fully mechanized top coal caving mining were the key issue to be noted in the coal mining industry,in order to provide the basic references to the powered support selection and the face roof management.Taking 217 coal mining face as an example,the pressure recorder of the powered support was applied to on-timely record the working resistance of the powered support.In combination with the strata pressure behaviors of the coal mining face,the roof pressurized features was analyzed.With the analysis on the resistance variation of the powered support at the top coal caving stage and at the no top coal caving stage,the differences of the roof pressurized features between the fully mechanized coal mining technique and the fully mechanized top coal caving mining technique were studied.The study results showed that in comparison with the fully mechanized coal mining,the powered support resistance at the fully mechanized top coal caving would be obviously increased,the dynamic load coefficient would be 1.30~1.41,the roof pressurized would be serious,the periodical pressurized distance of the basic roof would be obviously reduced from 22 m in average to 11 m in average.On the inclined orientation,the middle basic roof pressurized was most serious,the low section and top section of the basic roof pressurized were less serious.