Abstract: Study of disturbing effects of mining activity to thick aqueous soil layer could provided scientific guarantee basis for safety mining of hidden mine below thick aqueous soil layer and had practical significance.Took 13021 working face of a coal mine at Yongcheng in Henan province as the study model, engineering geological model established through relative geological conditions and by means of finite element method, relative study was done on stress path and strength characteristics of specific monitoring position at bottom aquifer in mining process, the result indicated stress state and volumetric strain of each points were both controlled by working face advancing distance, which explained changing mechanism of mining water pressure at a certain degree.

Key words: Bottom aquifer, Stress path, Mining, Numerical analysis