The stability analysis of the protection pillar under railway coal mining

When coal mining under the railway, the surface deformation caused by coal mining must be less than the railway allowed. The stability of the protection pillar is an important factor that affects nearly the surface deformation. Therefore, the stability of protection pillar is the key to coal mining under the railway. In this paper we determine the relationship between the coal pillar width and protection pillar stability through the protection pillar stress distribution and stress concentration analysis, and we also study the impact of the roof subsidence in different width of protection pillar by FLAC3D numerical simulation software. So put forward three kinds of schemes, in order to draw the reasonable width of coal protection pillars by comparative analysis. The safe of the railway and good economic can be achieved.