Determination of bearing capacity of wide coal pillars

Abstract

Wide coal targets are considered to be interstorey and barrier targets for various purposes, the width b of which is many times greater than the height t, and the length L significantly exceeds the width. In conditions of gentle bedding of seams such pillars under the action of active compressive load - the weight of overlying rocks - work on crushing. The material of the exposed surfaces of the pillar is in a stressed state, which can be considered as flat compression in the first approximation. As one moves away from the outcrop planes into the depth of the pillar, the stress state changes to volume compression, and the horizontal stress component increases from the edges to the middle of the pillar. The nature of the stress state also varies with the height of the pillar: the horizontal component of stress decreases with distance from the contacts with the host rocks ...