Analysis on stress distribution law of deep stratum and effect of regional tectonics in Shuangyashan Coal Mining Area

In-situ stresses are measured at 22 different points in different mining level from seven coal mines of Shuangyashan coal mining area by means of boring stress-relief method with hollow inclusion triaxial strain gauge. Though the stress measurement data discreteness is very great under the influence of the composite superimposition of multi-stage tectonic movement,the horizontal stress is predominate in depth and the value of the maximum horizontal principal stress is more than 30 MPa,the type of stress field belongs to σH>σh>σv. The variation of maximum horizontal principal stress,coefficient of horizontal pressure and horizontal differential stress almost linearly increase with depth,average angle of the maximum principal stress direction is 169.73°,which is almost NW-SE nearly horizontal. The regional rock mass is obviously affected by shear and the dynamic pressure disasters is frequently because the value of average horizontal differential stress is 17.52 MPa and the ratio of stress gradient and constant term is lager in the principal stress regression equation. Furthermore,according to the distribution of tectonic space in Shuangyashan coalfield,the geologic stress distribute in "mountain" glyph which was made by the north-south extrusion in long time. Combined with the results of in-situ stress,it can be used as an important reference for deep mining design and regional dynamic zone.