Study on geo- stress measurement and distribution features in Jibei Mining Area

A geostress influence was an important factor of the surrounding rock stability in the mine roadway. In order to have the geostress distribution features of Ji bei Mining Area,there were 9 typical in- situ stress measuring points selected in Jibei Mining Area and a stress release method was applied to a 3D geostress measurement conducted in Jibei Mining Area. The measuring results showed that a max horizontal stress,min horizontal stress and vertical stress in Jibei Mining Area increased linearly with the depth increase,a ratio of the max and min horizontal stresses was 1. 83 ~ 2. 68,the difference between the max and min stress was high and thus the internal shea r stress in the rock mass increased. The direction of the max major stress was close to NW- SE mainly and the inclination was close to the horizontal direction. Partial area at the middle west of the mining area was affected by the fold,the geostress was close in an east and west direction,the max horizontal stress was 1. 36 ~ 1. 82 times high er than the vertical stress. The structure stress was highly influenced to the west area of the mining area than the east area. Based on geostress measured results,the und erground mine roadway in Jibei Mining Area could be rationally made,the heading direction of the mine roadway should be in a NW- SE direction and the mine roadways in partial area should be adjusted according the measured results.