Analysis on stability of pillar and stiff roof system in the gob area

Abstract

Based on the open stope method, the stability of the gob area was decided by pillars and stiff roof. Therefore, it was dispensable to leave pillars with long-term strength and enough size to support the stiff roof during mining activities. Based on the mining conditions of Baixiang wollastonite mine in Changxing County of Zhejiang, while considering pillars with different shape, irregular size, and distribution, the load imposed on the pillars was analyzed, and the safety coefficient was calculated in order to determine their support status. The strength of stiff roof was calculated by means of analytical solution—theory of rectangle thin plate rested on elastic foundation. The system stability of pillar and stiff roof was analyzed according to the proportion of the total cross section area of pillars to the stiff roof area above the mined area.