Mining Theory of Automatically Formed Roadway (AFR)

In Chap. 2, the gob-side entry driving method was analyzed in a non-balance state in terms of mine pillar stress, overlying rock structure movement, and roadway support system. The mining damage invariant equation was proposed, and a short cantilever beam structural model for mining was established. The broken expansion function equation and roadway broken expansion control equation for the roof collapse of AFR without mine pillars were obtained. Combining upper bound method, the mechanical model of AFR roof zoning control was established. According to the stress characteristics of the short cantilever beam roof at different zones of the AFR, support forces are designed for three zones including the pre-splitting implementation zone, the pre-splitting influence zone and the pre-splitting stabilisation zone. It provided a theoretical basis for the design of AFR control parameters in different zones.