Study on Pillar Design Formula of Mining Face with Partial W-type Ventilation

In order to solve the problem in setting up the reasonable pillar size of mining face with partial W-type ventilation,by analysis and research of small pillar at the stage of tunneling and mining,thus the mechanical model is scientifically proposed. On the basis of the elastic-plastic limit equilibrium theory,the paper puts forward design formula for mining face with partial W-type ventilation by applying correlation theory of damage mechanics. By applying this design formula,the coal pillar's width at 090506 face in Duanwang mine is calculated,with the result of width of13. 3 m and shorten by 3. 3 meters compared to the original design. The results obtained finally demonstrate that the design formula is accurate and applicable by the means of Flac3 Dnumerical simulation to 090506 working face.