Abstract：To work out the reasonable position of floor drainage lane in outburst mines,eight designing positions combined with the geological conditions of a coal mining working face in west Henan are numerically simulated by means of FLAC3 D. Besides the roadway surrounding rock stress distribution and deformation characteristics from numerical simulation,economic factors and operating situation on site are also considered,the optimal design scheme is determined. It is revealed by the results that the three position that are vertical distance5. 8 m,vertical distance 10 m,and horizontal distance 10 m and 15 m respectively can all meet the requirements of roadway stability. However considerations economy,the best position is both the vertical and horizontal distance 10 m between roadway and bottom lane. The practice shows that the best position can meet the requirements of safety production,and the gas concentration after drainage is in the scope from 3. 3 m3/ t to 5. 8m3/ t,which is effective to reduce the gas outburst. The results can not only guide the coal safety and efficient production,but also provide a reference for similar geological coal mines.

Keyword：floor drainage lane;gas drainage;the maximum principal stress;plastic zone;