The Study on Ground Stress Measurement and the Stress Distribution Rule on E-W both Sides of Fault F_(17) of Ore Body II in Jingchuan Orefield

摘要

The comprehensive study results of variation rule of the stress in the orefield following the measurement depth had been done by mainly put forward the ground stress measurement of level 1200m, 1150m and 1000m of ore body II in Jinchuan orefield. The dimension and direction of ground stress of 16 points on E-W both sides of fault F_(17) are abtained by these measurements. The study result shows that the average of maximum principal stress of west fault F_(17) is about 25MPa, whereas that east of this fault is 20MPa. The general direction of maximum principal stress is NE-NNE, with somewhat local variation. The principal level of horizontal stress weakens progressively in the deep mining area. Nevertheless, the situation of different part of each level isn't the same as one another. The increase of difference between dimensions of maximum and minimum principal stress shows the increase of shear stress in the deep mining area and the increase of intensity of shear damage. Above the buried depth 500—600m, the maximum principal and horizontal stress shows a linear increase following the increase of depth, whereas the tendency of increase becomes gentle beneath the buried depth 500—600m.