Study on Ground Subsidence Law for Paste Backfill Fully Mechanized Coal Mining Face

In order to predict ground subsidence for paste backfill fully mechanized mining accurately and protect the surface buildings effectively, the ground subsi dence law and prediction parameters for paste backfill fully- mechanized coal mining face had been studied deeply through the comprehensive application of the theoret ical studies, inside test, field observation and numerical simulation. The results showed that the backfill body strength from 1 ~ 3 days early increased quickly, the backf ill body strength tended to be stable after seven days, the ultimate strength of backfill body was slightly below coal body; the phenomenon of ground appeared at the bo undary of mining influence, the tangent value of main impact angle was much smaller, and the scale of its influence was larger; the ground subsidence prediction param eters for paste backfill mining in Daming Mine had been got, based on the probability integral method, subsidence factor for paste backfill was 0.19 ~ 0. 22 times that f or fall down coal mining. To improve prediction accuracy, the model need to be modified when predicted ground subsidence of paste flling with probability integral meth od.