Abstract: To solve the safety problem of coal mining above confined water, based on the engineering background of paste filling mining above confined water in Zhucun colliery of Henan Energy and Chemical Industry Group, using the theoretical calculation, numerical simulation analysis and field measurement method, failure laws of floor and evolution characteristics in paste filling mining have been studied , and prediction research of floor failure scope and water-inrush character of paste filling mining has been conducted, which has in the end revealed the mechanical mechanism of control floor failure in paste filling mining. Research has shown that the floor failure depth increases with the increase of mining height, but when added to a certain height (1.8 m), the floor failure depth tends to a relatively stable value; paste filling fully mechanized mining can make floor failure depth of about 12.0 m by the method of caving mining, reduce to about 2.0 m, and the water inrush coefficient reduce from 0.19-0.56 to 0.08-0.20. Actual measurement has shown that the maximum floor failure depth in full area of paste filling fully mechanized mining is about 4 m, and in area influenced by fault ranges from 10.0 m to 12.0 m. Water inrush disaster has not appeared in any process of paste filling fully mechanized mining, and the safety degree of mine extracting has been improved by lowering mining height and relatively increasing the thickness of water-resisting floor.

Key words: paste-filling, failure floor, aquifer mining, confined aquifer