Site measurement on surface subsidence occurred by coal mining with high cutting height under complicated conditions in Bulianta Mine

In order to study the surface ground migration law after the coal mining performances of the fully mechanized high cutting one passing coal mining face under the different conditions of the shallow depth seams in Bulianta Mine,(as longwall mining goaf,coal pillar area and Wongawilli mining area),a mobile surface observation station was applied to the site measurement and analysis on the surface subsidence above the 32301 coal mining face equipped with high cutting height hydraulic powered supports in Bulianda Mine.The results showed that the surface movement features above the longwall mining goaf and coal pillar area would be obvious different caused by the 32301 fully mechanized full cut mining face with full cut hydraulic powered support.The max subsidence rate above the longwall mining goaf was faster than the coal pillar area.The lagging distance of the max subsidence rate was shorter than the coal pillar area.The subsid- ence coefficient Of the longwall goaf and the coal pillar area was 0.78 and 0.51 individually.The max subsidence rate of the longwall min- ing goaf was 490 mm per day and the lagging distance of the max subsidence rate was 61 m.The max subsidence rate of the coal pillar ar- ea was 234 mm per day and the lagging distance of the max subsidence rate was 80 m.